A session of the 60-member general assembly of the Islamist-dominated coalition will also elect a new head and discuss the fate of provisional prime minister Ghassan Hitto, who has come under heavy criticism for being too influenced by opposition figures with close links to Qatar, coalition insiders said.

In an effort to widen the appeal of the coalition, backed by Saudi Arabia, Hitto is likely to be replaced by Ahmad Tomaa Kheder, an independent Islamist from the eastern Syrian province of Deir al-Zor. He worked closely with liberals in peaceful opposition to President Bashar al-Assad before the war, the sources told Reuters.

“Everything will be decided in the general assembly meeting,” said one of the coalition officials.

“The meeting will decide on accepting the nomination of Kheder, although Hitto is trying to hang on,” another coalition source said.

In recent weeks, Saudi Arabia has increased its efforts to court the Syrian opposition as the kingdom takes a bigger role in trying to bridge differences within the anti-Assad camp, diplomats based in the region said. Together with Qatar, Saudi Arabia is the main Arab backer of Assad’s foes on the ground.

A blow has been dealt to the opposition’s unity by the resignation of the coalition’s maverick president Moaz Alkhatib in March.

Alkhatib, who had offered Assad a negotiated exit, has been meeting the coalition’s 11-member leadership committee in Istanbul over the past two days, the sources said.

The committee has so far failed to reach agreement on the peace conference, which Washington and Moscow want to hold by the end of the month.

FUTURE OF ASSAD

“Without a firm indication that the conference will be about arranging the departure of Assad, it will be impossible for the coalition to attend without losing its credibility with the people of Syria,” another coalition insider said.

“On the other hand there is a feeling that the United States is going along with Russia in a last-ditch effort ahead of embarking on military action that will help remove Assad.”

Among the strongest contenders to replace Alkhatib are George Sabra, a veteran Christian opposition figure who is the acting president of the coalition, and Burhan Ghalioun, a liberal professor based in France who had campaigned for democratic change in Syria since the rule of Assad’s late father, coalition insiders said.

Since the coalition was set up with Gulf and Western backing at the end of last year, two power centers have emerged; the powerful Muslim Brotherhood and its allies and another faction led by the coalition’s Secretary General Mustafa Sabbagh, who has close links with Qatar, opposition sources said.

A shake-up appears under way. The meeting of the general assembly on May 23 will discuss bringing in members of a secular-leaning camp currently being established in Cairo by prominent opposition figures who had previously stayed away from the coalition.

They include Michel Kilo, a writer who was jailed for three years before the revolt after he criticized repression and domination by the Assad clan.

Russia said on Saturday there was disagreement over who should represent the opposition in a Syrian peace process, days after Moscow and Washington announced the joint effort to bring the two sides to an international conference.

Moscow has been Assad’s main protector and weapons supplier and says that, although it is not wedded to him, it will not allow his departure to be made a precondition of talks, as sometimes demanded by Western and Gulf powers.

U.S. Secretary of State John Kerry said on Saturday Assad’s exit should be the outcome of negotiations on a transitional government, rather than the starting point.

(Editing by Andrew Roche)

Around Damascus the warplanes staged a series of raids in the early hours of Sunday including on President Bashar al-Assad’s air defenses, opposition and rebel sources said. But none had more devastating results than at Hameh, a high-walled site linked to his chemical and biological weapons program.

“Families ran to basements and stayed there,” said one witness of the attack on Hameh that lit up the night sky and shook the ground kilometers (miles) away. “We heard ambulances. There were very few workers at the compound at that time but an attack of this scale must have killed a lot of soldiers among the guards and patrols.”

The raids have raised fears that Israel could be drawn into Syria’s civil war, in which the United Nations says 70,000 people have died since an uprising against Assad family rule began two years ago. Damascus has accused Israel of effectively helping what it calls al Qaeda Islamist terrorists.

Western intelligence sources said the attacks were designed to prevent Syria sending Iranian-supplied missiles to the Shi’ite Hezbollah group in neighboring Lebanon for possible use against Israel. An Israeli general played down the consequences on Monday, saying: “There are no winds of war”.

The witness said windows were blown out in workers’ flats several hundred meters (yards) from Hameh’s perimeter, even though the centre of the blasts was further away on the huge site, which is surrounded by air defenses.

Opposition sources said the warplanes also hit facilities manned by Assad’s Republican Guards on Mount Qasioun, which overlooks central Damascus, and the nearby Barada River basin.

The area is believed to be a supply route to Hezbollah, according to residents, activists and opposition military sources. Their statements could not be verified due to restrictions on media operating in Syria.

RIGHT ON TARGET

One rebel commander said Assad’s forces have been fortifying their positions on Qasioun since the uprising began in March 2011. “The Israelis still managed to get to the weapons stores. The secondary explosions indicate that they were right on target,” he said, adding that Syrian air defenses, already weakened by the civil war “could not do anything”.

Other opposition sources also said the targets included air defenses comprising Russian-made surface to air missiles and heavy anti-aircraft guns, deployed on Qasioun and overlooking the rebellious Damascus district of Barzeh.

“The destruction appeared to be massive. We have heard that the army has asked rank and file personnel based in Qasioun and those on leave to stay away. The military usually does this sort of thing when there is a big mess to sort out,” said one activist in Damascus, who did not want to be named.

Assad’s forces have fired on rebels from Qasioun, which is largely a closed military zone apart from a strip of restaurants, flattening areas of Damascus below.

However, it was unclear whether Israel was effectively helping the rebels by raiding the Qasioun sites, as Damascus has said, or attacked the air defenses purely to safeguard its own operations against Iranian-supplied missiles.

The Syrian government has said that Israel raided three military sites. Several media published what they described as a photo supplied by the official Syrian news agency showing a huge pile of collapsed concrete at a flattened building in an unspecified site they said was targeted by the Israelis. Reuters could not verify the photo.

Turkish Prime Minister Tayyip Erdogan, a strong opponent of Assad, said on Tuesday the Israeli air strikes had given the Syrian government an opportunity to cover up its own killings.

“The air strike Israel carried out on Damascus is completely unacceptable. There is no rationale, no pretext that can excuse this operation,” Erdogan told parliament in Ankara.

Opposition sources familiar with the Hameh site said a large section of the compound housing missile systems appeared to have been hit. Mobile missile launchers, part of a Russian-supplied SA-17 air defense system deployed elsewhere on Qasioun, also appear to have been destroyed, they said

Western intelligence agencies suspect work on chemical weapons has been conducted at Hameh. Assad’s government and the rebels have accused each other of carrying out three chemical weapons attacks, one near Aleppo and another near Damascus in March, and another near Homs in December.

The Syrian Observatory for Human Rights, an opposition monitoring group based in Britain, said at least 42 Syrian soldiers were killed and 100 others are missing.

Other opposition sources put the death toll at 300 soldiers, mostly belonging to the Republican Guards, an elite unit that forms the last line of defense for Damascus and comprises mainly members of Assad’s Alawite sect, an offshoot of Shi’ite Islam that has controlled Syria since the 1960s.

Although casualties among Assad’s troops appeared to be high, opposition sources said the raids were mainly targeted on storage facilities. “Whatever they hit, there is little chance that anything was left intact,” another source in Damascus said.

(editing by David Stamp)

Oil prices spiked above $105 (67.5 pounds) a barrel, their highest in nearly a month, on Monday as the air strikes on Friday and Sunday prompted fears of a wider spill over of the two-year-old conflict in Syria that could affect Middle East oil exports.

“There are no winds of war,” Yair Golan, the general commanding Israeli forces on the Syrian and Lebanese fronts, told reporters while out jogging with troops.

“Do you see tension? There is no tension. Do I look tense to you?” he said, according to the Maariv NRG news website.

Israeli Prime Minister Benjamin Netanyahu came under veiled criticism in Beijing, where he began a scheduled visit in an apparent sign of confidence Syrian President Bashar al-Assad would not retaliate. China urged restraint without mentioning Israel by name.

Russia, Assad’s other protector on the U.N. Security Council, said the strikes by Israel “caused particular alarm”. President Vladimir Putin and U.S. Secretary of State John Kerry will meet on Tuesday to try to tackle differences over the Syrian crisis.

Israeli officials said the raids were not connected with Syria’s civil war but aimed at stopping Hezbollah, an ally of Iran, acquiring weapons to strike Israeli territory.

Israel aimed to avoid “an increase in tension with Syria by making clear that if there is activity, it is only against Hezbollah, not against the Syrian regime,” veteran lawmaker Tzachi Hanegbi, a confidant of Netanyahu, told Israel Radio.

MOST CASUALTIES FROM ELITE UNIT

The Syrian Observatory for Human Rights, an opposition monitoring group based in Britain, said at least 42 Syrian soldiers were killed in the strikes and 100 were missing.

Other opposition sources put the death toll at 300 soldiers, mostly belonging to the elite Republican Guards, a praetorian unit that forms the last line of defence of Damascus and includes mainly members of Assad’s Alawite sect, an offshoot of Shi’ite Islam that has controlled Syria since the 1960s.

As well as the heavily fortified Hamah compound, linked to Syria’s chemical and biological weapons programme, the warplanes hit military facilities manned by Republican Guards on Qasioun Mountain overlooking Damascus and the nearby Barada River basin.

Residents, activists and rebel sources said the area is a supply route to the Lebanese Shi’ite militant group Hezbollah, but missiles for Hezbollah did not appear to be the only target.

Air defences comprising Russian-made surface-to-air missiles and anti-aircraft guns on Qasioun and overlooking the rebellious Damascus district of Barzeh were also hit, they said. Their statements could not be verified due to restrictions on media.

“The destruction appeared to be massive,” said one activist in Damascus, who did not want to be identified.

Russia said it was concerned the chances of foreign military intervention in Syria were growing, suggesting its worry stemmed in part from reports about the alleged use of chemical weapons in the conflict that has killed 70,000 people.

“The further escalation of armed confrontation sharply increases the risk of creating new areas of tension, in addition to Syria, in Lebanon, and the destabilisation of the so-far relatively calm atmosphere on the Lebanese-Israeli border,” Russian Foreign Ministry spokesman Alexander Lukashevich said.

Assad’s government accused Israel of effectively helping al Qaeda Islamist “terrorists” and said the strikes “open the door to all possibilities”. It said many civilians had died but there was no official casualty toll.

CALCULATING

Israeli officials said that, as after a similar attack in the same area in January, they were calculating Assad would not fight a well-armed neighbour while preoccupied with survival against a revolt that grew from pro-democracy protests in 2011.

Israel has not confirmed the latest attacks officially, but has reinforced anti-missile batteries in the north. It said two rockets landed, by mistake, on Monday, in the Golan Heights, the Israeli-occupied area near Syria’s border with Israel.

“They were fired erroneously as a by-product of internal conflict in Syria,” an Israeli military spokesman said.

Syria would be no match for Israel in any direct military showdown. But Damascus, with its leverage over Lebanon’s Hezbollah, could consider proxy attacks through Lebanon.

Tehran, which has long backed Assad, whose Alawite minority has religious ties to Iran’s Shi’ite Islam, denied Israel’s attack was on arms for Hezbollah. Hezbollah did not comment.

Moscow and Beijing have blocked Western-backed measures against Assad at the United Nations Security Council, opposing any proposal that has his exit from power as a starting point.

Allegations of the use of chemical weapons – long described by Western leaders as a “red line” that would have serious consequences – have added to regional and international tension.

After months of increasingly bitter fighting, Assad’s government and the rebels have each accused the other of carrying out three chemical weapon attacks.

In Washington, an influential U.S. senator introduced a bill on Monday that would provide weapons to some Syrian rebels.

Democratic Senator Robert Menendez, chairman of the Senate Foreign Relations Committee, said in a statement that Assad had crossed a red line and “the U.S. must play a role in tipping the scales toward opposition groups”.

President Barack Obama has taken a cautious approach to the reports of the use of chemical weapons in Syria, saying he would not allow himself to be pressured prematurely into deeper intervention in the conflict.

The White House has said the Syrian government has probably used chemical weapons. A U.S. official said on Monday Washington had no information to suggest that rebels had used them.

Syria is not part of the international treaty that bans poison gas but has said it would never use it in an internal conflict. Rebels say they have no access to chemical arms.

A U.N. inquiry commission said on Monday war crimes investigators had reached no conclusions on whether any side in the Syrian war has used chemical weapons, after a suggestion from one of the team that rebel forces had done so.

(Additional reporting by Alexei Anishchuk in Moscow, Michael Martina in Beijing, Marwan Makdesi in Damascus, Jonathon Burch in Ankara and Patricia Zengerle in Washington Writing by Philippa Fletcher; Editing by Peter Graff and Mohammad Zargham)

Oil prices spiked above $105 a barrel, their highest in nearly a month, on Monday morning as the air strikes on Friday and Sunday prompted fears of a wider spillover of Syria’s two-year-old civil war that could affect Middle East oil exports.

Israel, whose prime minister visited China on Monday in a sign of business-as-usual, sought to persuade Syrian President Bashar al-Assad on Monday that the air strikes did not aim to weaken him and dismissed the prospects of an escalation.

“There are no winds of war,” Yair Golan, the general commanding Israeli forces on the Syrian and Lebanese fronts, told reporters while out jogging with troops.

“Do you see tension? There is no tension. Do I look tense to you?” he said, according to the Maariv NRG news website.

The attacks hit targets manned by Assad’s elite troops in the Barada River valley and Qasioun Mountain, residents, activists and opposition military sources said. They included a compound linked to Syria’s chemical weapons program, air defenses and Republican Guards’ facilities, the sources said.

The Syrian Observatory for Human Rights said at least 42 soldiers were killed and 100 more were missing, while other opposition sources put the death toll at 300 soldiers.

Russia said it was concerned the chances of foreign military intervention in Syria were growing, suggesting its worry stemmed in part from media reports about the alleged use of chemical weapons in the conflict that has killed 70,000 people.

Russian Foreign Ministry spokesman Alexander Lukashevich said the reported air strikes “caused particular alarm”.

“The further escalation of armed confrontation sharply increases the risk of creating new areas of tension, in addition to Syria, in Lebanon, and the destabilization of the so-far relatively calm atmosphere on the Lebanese-Israeli border.”

Assad’s government accused Israel of effectively helping al Qaeda Islamist “terrorists” and said the strikes “open the door to all possibilities”. It said many civilians had died.

IRAN

Israel has not confirmed the attack officially, but has reinforced anti-missile batteries in the north. Israeli officials said that, as after a similar attack in the same area in January, they were calculating Assad would not pick a fight with a well-armed neighbor while preoccupied with survival.

Syria would be no match for U.S. ally Israel in any direct military showdown. But Damascus, with its leverage over Lebanon’s Hezbollah, could still consider proxy attacks through Lebanon.

Israeli officials said the raids were not connected with Syria’s civil war but aimed at stopping Hezbollah, an ally of Iran, acquiring weapons to strike Israeli territory if Israel were to attack Iranian nuclear sites.

Iran denies Israeli and Western accusations that it is bent on acquiring atomic weapons – a long-running dispute that now threatens to intersect with the bloody strife in Syria.

Tehran, which has long backed Assad, whose Alawite minority has religious ties to Shi’ite Islam, denied Israel’s attack was on arms. Shi’ite Hezbollah did not comment.

China, hosting Netanyahu, urged restraint and the respect of sovereignty, without mentioning Israel by name. Moscow and Beijing, allies of Assad, have blocked Western-backed measures against Assad at the United Nations Security Council.

A U.S. official said U.S. Secretary of State John Kerry was due to meet Russian President Vladimir Putin on Tuesday to see if he could persuade Moscow to support U.S. peace efforts.

Following the air strikes, the United Nations said Secretary-General Ban Ki-moon called on all sides “to act with a sense of responsibility to prevent an escalation of what is already a devastating and highly dangerous conflict”.

The military in Turkey, one of Assad’s most vocal critics and home to more than 400,000 refugees from the civil war that grew out of protests against his rule, launched a 10-day military exercise on Monday at a base near the border.

The violence in Syria has inflamed wider regional tensions between Shi’ite Muslim Iran and Sunni-ruled Arab states, some of them close allies of the West.

Senior Republican Senator John McCain said on Sunday that the Israeli air strikes could add pressure on Washington to intervene in Syria, although President Barack Obama has said he has no plans to send ground troops.

After Friday’s raid, Obama defended Israel’s right to block “terrorist organizations like Hezbollah” from acquiring weapons. A U.S. intelligence official said on Sunday Washington was not given any warning before the air strikes.

(Additional reporting by Alexei Anishchuk in Moscow, Michael Martina in Beijing, Marwan Makdesi in Damascus and Jonathon Burch in Ankara; Writing by Philippa Fletcher; Editing by Peter Graff)

Similar concerns among Syria’s other neighbors, including Turkey and Israel, are complicating an already disjointed world response to the bloody turmoil at the heart of the Middle East.

Jordan has allowed limited U.S. military training of rebels on its territory. Some other fighters have crossed from the kingdom into Syria, although others, especially Islamists, have been intercepted and even put on trial.

Eighteen months ago, Jordan’s King Abdullah was the first Arab leader to urge Assad to step aside, but he used a visit to Washington last week to voice Jordan’s concern over “militant terrorist organizations” gaining ground along Syria’s southern frontier with the kingdom.

His comments in the Oval Office alongside U.S. President Barack Obama underline fears that Jordan’s national security is now threatened by Islamists in Syria whose hatred of Assad is matched only by their hostility to the pro-Western monarchy.

As a result, senior diplomats in Amman say, Jordan has resisted pressure from Gulf Arab states to step up arms shipments to rebels it believes might one day turn against it.

Jordan is also concerned that Syria, which is widely believed to possess chemical weapons, might lash out in reprisal for any heightened Jordanian support for insurgents.

“The fire will not stop at our border and everybody knows that Jordan is as exposed as Syria,” Assad said two weeks ago in an interview which depicted al Qaeda as a security concern for both countries – a message which resonated with many Jordanians.

Syria’s rebel Nusra Front, one of the deadliest forces fighting to topple Assad, declared its allegiance to al Qaeda leader Ayman Zawahri earlier this month, formally cementing an alliance with a group which has targeted Jordan in the past.

At the same time, Nusra Front fighters and other rebels have opened a new battlefront in southern Syria, a move which Assad blamed on the infiltration of thousands of militants from Jordan, seizing military posts and swathes of land.

“The security threat comes from the Nusra Front and the radical Islamic groups – if they win and are stationed on the Jordanian border, that causes problems from the army’s perspective,” said retired Jordanian Major-General Fayez Dwairi.

Jordanian officials, who asked not to be identified, said limited security cooperation with Damascus was continuing.

JORDAN JITTERS

As well as the danger of fighting spilling over its border from Syria’s southern province of Deraa, Amman faces the familiar threat of young Jordanians joining a regional conflict and then returning home, battle-hardened and radicalized.

Jordanian-born Abu Musab al-Zarqawi travelled to Afghanistan in the 1980s and also fought in Iraq, from where he was believed to have planned attacks on hotels in Amman which killed dozens of people in November 2005.

With the Syrian border just 75 miles from Amman, the conflict in Jordan’s northern neighbor is much closer to Abdullah’s capital than the turmoil in Iraq ever was.

So although Jordan has allowed the training of rebels on its territory and permitted some Gulf-funded arms shipments into Syria, it has rebuffed pressure to send larger consignments into the war zone, according to diplomats.

“Jordan national strategic interests come first and before any Gulf agenda,” said a senior security official who asked not to be named, singling out Qatar for what he said was a flawed policy of empowering the Muslim Brotherhood, a longtime adversary of Jordan’s monarchy.

The Brotherhood’s political wing in Jordan, the Islamic Action Front, has taken part in protests calling for political reform and denouncing subsidy cuts in the resource-poor kingdom, which relies on Gulf grants to narrow its gaping budget deficit.

Publicly, Jordan says it remains neutral in the conflict.

Prime Minister Abdullah Ensour has even denied in parliament that Jordan hosts rebel training programs – contradicting accounts from rebels and diplomats – and said the kingdom opposed any military intervention to overthrow Assad.

Jordan’s jitters were illustrated last month, rebels say, when it warned them not to seize the main Nasib border crossing. They said Jordanian forces also detained and interrogated local weapons smugglers to curb the flow of small arms into Deraa.

Shortly afterwards Washington announced it would send an Army headquarters unit – which could theoretically command combat troops. Jordan has also beefed up its military capability on the border and requested U.S. Patriot batteries to protect it from any retaliatory missile attack from Assad’s forces.

TURKEY FEARS

Syrian rebels have received military supplies via Turkey, which also frets about the rise of radical Islamists among the insurgents, fearing greater security problems along its 900 km border should they rise to prominence in a post-Assad Syria.

Those concerns are limiting direct support to the opposition from Syria’s northern neighbor, Turkish officials say.

“Turkey is at least as concerned as the U.S. and other allies about al Nusra. Turkey also thinks that the continuation of the current situation will feed more extremism,” said a source close to the Turkish government.

Disunity among rebels, rival allegiances and Western fears of being sucked into an open-ended conflict in which Russia and Iran back Assad have already obstructed any concerted foreign response to the crisis.

But doing nothing will let the balance of forces on the ground shift towards radical Islamists, said Sinan Ulgen of the Istanbul-based Centre for Economic and Foreign Policy Studies.

Another neighbor watching anxiously is Israel, whose forces occupy the Golan Heights southwest of Damascus and which shares Jordan’s concerns over the spread of Islamist fighters.

Western diplomats familiar with Jordanian thinking and rebel commanders on the ground say Jordan appears to be channeling weapons to moderate rebels inside Syria to protect its border – a move which might also indirectly address Israeli concerns.

The two countries signed a peace deal in 1995 and have worked closely together since then on regional security.

But Amman’s limited support frustrates rebels who say that rudimentary two-week weapons training for hundreds of fighters will do little to tilt the military balance against Assad.

“There are growing suspicions about Jordan’s ultimate goals in (Syria) and the way they are starting to form militias loyal to them,” said Abu Haytham, a rebel commander of Ababeel Hauran, an Islamic brigade. He accused the kingdom of backing Syrian forces ready to confront the Islamists after Assad falls.

Another rebel commander, Abu Omar, who lost an eye in street fighting in the southern city of Deraa, cradle of the revolt against Assad, called for more sophisticated weaponry.

“If the Jordanians supply us with anti-aircraft and anti-tanks weapons we will finish Deraa in a week, and not much later we will be at the gates of Damascus,” the 37-year-old former trader told Reuters in Jordan’s northern city of Irbid where he was being treated for shrapnel wounds.

Video footage of rebels in southern Syria has shown them wielding anti-tank weapons and heavy caliber rifles. Some appeared to have been supplied from outside Syria, but rebels say most were seized from captured army bases.

According to regional diplomats, whose accounts tally with those of rebels spoken to by Reuters, Jordan’s intelligence services sent a few shipments of light arms to a Jordanian-backed rebel military council, but the supplies soon dwindled.

As one rebel commander described it: “The Jordanians would say, ‘Wait a bit, a weapons shipment is coming’. The rebels would wait one day, two days, or a month… In the end, the weapons that arrived were damaged and insufficient.”

(Additional reporting by Nick Tattersall in Istanbul; Editing by Dominic Evans and Alistair Lyon)

The attack targeted buildings belonging to the Ahrar al-Sham, a Salafist Islamist rebel unit fighting to topple Syrian President Bashar al-Assad, the activists said. A Turkish aid worker said the strike also hit a warehouse on the Syrian side of the border used by aid groups.

“The target appears to be Ahrar al-Sham but most of the fighting brigades have a presence at and around the crossing and it is impossible to get them without harming civilians,” said Mohammad, an activist at the crossing, who gave only his first name.

“This is the closest air strike we have seen to the border. The crossing had been seen as a safe haven before,” he said.

Health officials in the Turkish border town of Reyhanli said the local hospital there, which frequently receives Syrian patients from just over the border, had taken “precautions” because of unconfirmed reports that some of the wounded may have come into contact with chemical weapons.

Some Syrian activists said some of the casualties were suffering breathing difficulties but said they did not know what type of munitions had been used in the attack.

“We cannot confirm that there were any chemical weapons involved,” Reyhanli mayor Huseyin Sanverdi told Reuters.

U.S. President Barack Obama on Tuesday said there was evidence that chemical weapons were used inside Syria but questions remained about their use.

A senior hospital official in Reyhanli said approximately 50 people had been brought in but declined to comment on the nature of their injuries. A Syrian activist speaking from the hospital said more critical cases had been taken to another clinic.

Another activist at the Syrian Bab al-Hawa border gate said people waiting to cross were among those hit.

He added that at least 15 wounded were taken to hospital near the crossing on the Syrian side and among the dead were a one-and-a-half-year-old child and two teenage girls.

(Additional reporting by Ozge Ozbilgin in Ankara and Asli Kandemir in Istanbul; Editing by Nick Tattersall and Michael Roddy)

The fighting occurred near the Scientific Studies and Research Centre on the foothills of Qasioun Mountain in the northern Barzeh district, opposition sources said from Damascus.

Barzeh is one of several working class neighborhoods that have turned into footholds for opposition brigades, who have infiltrated Damascus from swathes of farmland dotted with built-up areas on the outskirts of Damascus known as al-Ghouta.

The rebels lack the firepower to breach the heavily fortified Research Centre complex and the compound is being used to shell Barzeh, the sources said.

The U.S. administration said last week that Assad’s forces had probably used chemical arms in the conflict and congressional pressure has mounted on the White House to do more to help the rebels.

Republican senators on Sunday pressed President Barack Obama to intervene, saying America could attack Syrian air bases with missiles but should not send in ground troops.

Neutralizing Assad’s air advantage over the rebels “could turn the tide of battle pretty quickly,” Republican Senator Lindsey Graham told a CBS news programme.

In Barzeh at least nine people were killed and 70 were wounded in the last three days, mostly from army shelling. The district is home to a military hospital, hit by rocket-propelled grenades and mortar rounds on Sunday, and an electronic eavesdropping facility, as well as a military police compound and another army unit, the sources said.

AIR RAID

Syrian warplanes bombed on Sunday the adjacent district of Qaboun, through which Barzeh is being supplied from the Ghouta. There were no immediate reports of casualties, according to activists in the neighborhood.

The Syrian official state news agency said “units of the heroic Syrian army have inflicted heavy losses on terrorists” in Barzeh, eastern Damascus and Ghouta.

Speaking form Barzeh, opposition activist Abu Ammar said the research center was the only military facility in Barzeh that the rebels have not managed to hit. He added that a chemical weapons storage facility is located near the center “It is very heavily fortified and there are heavy caliber anti-aircraft guns deployed in the complex and in large tracts of land that are part of it,” he said.

He said opposition fighters in Barzeh repulsed an attack on their strongholds in the district from the adjacent Ush al-Warwar area, part of several hilltop enclaves inhabited by Assad’s minority Alawite sect.

“Barzeh has been besieged for the last fifty days; with a narrow supply line to Ghouta through Qaboun,” Abu Ammar said.

“Fighting has intensified in the last three days and the regime sent down his militia today from Ush al-Warwar but the fighters forced them to turn back,” he added.

Activists reported fighting in the nearby district of Jobar to the south, where an air strike near a mosque set off a huge plume of white smoke, according to video footage taken by the opposition, as fighting continued across the Ghouta.

The army seized the town of Otaiba, near the Damascus International Airport, in Ghouta last week, cutting a weapons supply route into the eastern fringes of Damascus that rebels had used for eight months.

Syria’s uprising is the bloodiest and longest of Arab revolts that erupted more than two years ago.

It began with peaceful protests against Assad that were met with force, sparking armed opposition and eventually civil war pitting Assad’s minority Alawite sect against the Sunni Muslim majority.

The army appears to have made gains in the north and center of the country in recent weeks.

(Editing by Stephen Powell)

If the accounts are confirmed, the killings in the mainly Sunni Muslim suburb of Jdeidet al-Fadel would amount to one of bloodiest episodes of the two-year-old uprising against Assad. Many of the dead were civilians, the activists said.

A statement by the Syrian National Coalition umbrella opposition group, issued from Istanbul, said death toll “continues to rise and has reached the hundreds” and described the killings as a “horrifying civilian massacre”.

“The deafening silence of the international community over these crimes against humanity is shameful, and has become routine for the victims and their families,” the statement said.

“Syrians no longer expect an answer to our pleas for help or a chivalrous intervention from our brothers and neighbors. We no longer expect to be supported with the necessary arms to empower the Free Syrian Army to defend our people.”

Syrian state media gave no death toll but confirmed the army had been fighting in Jdeidet al-Fadel. It said it had saved the town from what it described as criminal terrorist groups, killing and wounding an undisclosed number of them.

On Sunday, activists said at least 85 people had been killed and the toll might reach 250, but with the army beginning to pull back they said more accounts were emerging which suggest the final figure could be even higher.

The activists, speaking from the area, 10 km (six miles) southwest of Damascus, said residents had buried some victims in the early stages of the five-day attack by elite forces and pro-Assad militias. More bodies were now being found burnt or apparently killed in summary executions, they said.

Rebel brigades who numbered around 300 fighters withdrew two days ago, they said, leaving Assad’s forces in total control.

The working-class district is one of several Sunni Muslim towns surrounding the capital that have been at the forefront of the uprising. It is situated near hilltop bases of elite forces which are mostly from Assad’s minority Alawite sect, an offshoot of Shi’ite Islam that has dominated Syria since the 1960s.

BODIES LYING IN STREETS

Shamel al-Golani, of the opposition Sham News Network, said one of the hardest hit areas was a neighborhood adjacent to the 100 army brigade, one of several elite units based around Jdeidet al-Fadel.

“In the first three days the army would go into neighborhoods and commit killings and withdraw and come back the next day,” he said.

“Many of them who were killed early were refugees from Daraya and al-Mouadamiya and were buried quietly,” he said, referring to two adjacent suburbs that have been the scene of fighting and several army incursions.

Assad’s forces have been accused of massacring hundreds of Sunni Muslims in areas they stormed in Hama and Homs provinces and Damascus suburbs. International rights groups say rebel forces have also committed atrocities, although on a smaller scale.

Jdeidet al-Fadel lies on the road from Damascus to the Israeli-occupied Golan Heights. Its residents are Golan refugees and in the last year thousands of families from nearby areas took shelter in the town.

The Syrian Organisation for Human Rights (Sawasiah), which put the death toll at 500, said the army forces included elite Republican Guards, the 100 and 153 artillery brigades and the 555 brigade, formerly known as the Defense Brigades.

Units of “sectarian militia” supported by members of air force intelligence, one of the most feared of a myriad of secret police branches, accompanied the army units, it said.

According to witness accounts interviewed by the Syrian organisation, water and electricity were cut off from the town and residents were not allowed to leave as Assad’s forces blocked ways in and out of the suburbs.

Many of the victims, Sawasiah said, were civilians, targeted because the suburb was an “incubator for armed resistance” and they had showed solidarity with refugees in adjacent towns also subjected to mass killings.

(Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Dominic Evans and Robin Pomeroy)

At least two towns held by Sunni Islamist rebels in the al-Qusair region near the Orontes River were overrun after sectarian clashes escalated early last week, threatening to bring in Iranian-backed Hezbollah openly into the battle, the sources said.

On Saturday, in the first attack well inside Lebanese territory, rockets hit the town of Hermel, a Hezbollah stronghold in the Bekaa Valley, causing damage but no casualties. A Hezbollah fighter was killed in the Shi’ite border town of Zita, inside Syria, residents said.

Six rebels were killed in clashes in the Syrian city of Qusair on Sunday and one woman was killed in Syrian air strikes in the region, opposition campaigners said.

The official Syrian state news agency Sana said “the brave Syrian army spread its control of (the town of) Saqraja after it destroyed the last remnants of the terrorists.”

The border area, known for decades for its smuggling, is an important supply route for rebels fighting President Bashar al-Assad’s forces in the central city of Homs, a main front in the war.

The conflict started two years ago with peaceful demonstrations against four decades of rule by the Assad family, who belong to the Alawite sect, an offshoot of Shi’ite Islam.

At least 70,000 people have been killed in the civil war, which is increasingly pitting majority Sunnis against the minority Alawites, who have controlled Syria since the 1960s.

The Syrian war has worsened Lebanon’s own sectarian tensions, with wounds from a 15-year civil war that ended in 1990 far from healed. Syrian maintained a 29-year military presence in Lebanon until it was forced to withdraw its troops under international pressure in 2005.

Assad, who has lost control of large parts of Syria, has been on the offensive in the centre and north of the country in the last few weeks.

In the border region, Syrian army troops and Shi’ite militias entered the towns of Saqraja, which controls the approaches to the main rebel-held town of Qusair, and al-Radwaniya, while intense fighting was reported in the nearby village of Burhaniya, the sources said.

A joint statement by the rebel command in Qusair and the al Qaeda linked al-Nusra front, broadcast on the opposition Orient Television, said the rebel brigades would “move the battle into Lebanon” if the Hezbollah-backed offensive continued.

The statement said rebels would use tanks and missiles to hit the mostly Shi’ite Lebanese city of Baalbek, home to famed ruins of a Roman temple, and move fighters into Lebanese territory to attack Hezbollah there.

PINCER MOVEMENT

Speaking from Qusair, activist Hadi al-Abdallah said Hezbollah and its militia allies were pushing from the Bekaa valley toward Qusair, while the Syrian army was moving south from Homs in a pincer movement aimed at ending the rebel presence along the border.

“In the last few days there have been attacks by the Hezbollah forces on new villages around Qusair,” he said, adding that Hezbollah and its allies had already taken eight villages and towns along the border inside Syria.

“This is part of a bigger strategy to control Homs and link it with the Bekaa and the coast,” he said, referring to Alawite regions near the Mediterranean where the opposition suspects Assad will rebase and form an Alawite enclave if his position in Damascus becomes untenable.

“We do not want to reach a stage where the rebels would have to hit Lebanese territory at random,” Abdallah said, adding that the opposition would hold their fire if the attacks on Qusair and the surrounding towns was called off.

(Additional reporting by Laila Bassam in Beirut; Editing by Stephen Powell and Robin Pomeroy)

At least two towns held by Sunni Islamist rebels in the al-Qusair region near the Orontes River were overrun after sectarian clashes escalated early last week, threatening to bring in Iranian-backed Hezbollah openly into the battle, the sources said.

On Saturday rockets hit the town of Hermel, a Hezbollah stronghold in Lebanon’s Bekaa Valley, causing damage but no casualties, and a Hezbollah fighter was killed in the Shi’ite border town of Zita inside Syria, residents said.

Six rebel fighters were killed in clashes in Qusair on Sunday and one woman was killed in Syrian air force bombing on the region, opposition campaigners said.

The border area, known for smuggling for decades, is an important supply line for rebels fighting President Bashar al-Assad’s forces in the central city of Homs, a main front in the war.

The conflict started two years ago with peaceful demonstrations against four decades of rule by the Assad family, who belong to the Alawite sect, an offshoot of Shi’ite Islam.

At least 70,000 people have been killed in the conflict, which is increasingly pitting majority Sunnis against the minority Alawites, who have controlled Syria since the 1960s.

The Syrian war has worsened Lebanon’s own sectarian tensions, with wounds from a 15-year civil war that ended in 1990 far from healed. Syrian maintained a 29-year military presence in Lebanon until it was forced to withdraw its troops under international pressure in 2005.

Assad, who has lost control of large parts of Syria, has been on the offensive in the centre and north of the country in the last few weeks.

In the border region, Syrian army troops and Shi’ite militias entered the towns Saqraja, which controls the approaches to the main rebel-held town of Qusair, and al-Radwaniya, while intense fighting was reported in the nearby village of Burhaniya, the sources said.

PINCER MOVEMENT

The official Syrian state news agency Sana said “the brave Syrian army spread its control of Saqraja after it destroyed the last remnants of the terrorists.”

Speaking from Qusair, activist Hadi al-Abdallah said Hezbollah and its militia allies were pushing from the Bekaa valley toward Qusair, while the Syrian army is moving south from Homs in a pincer movement aimed at ending the rebel presence along the border.

“In the last few days there have been attacks by the Hezbollah forces on new villages around Qusair,” he said, adding that Hezbollah and its allies had already taken eight villages and towns along the border inside Syria.

“This is part of a bigger strategy to control Homs and link it with the Bekaa and the coast,” he said, referring to Alawite regions near the Mediterranean where the opposition suspects Assad will rebase and form an Alawite enclave if his position in Damascus becomes untenable.

“We do not want to reach a stage where the rebels would have to hit Lebanese territory at random,” Abdallah said, adding that the opposition would hold their fire if the attacks on Qusair and the surrounding towns was called off.

(Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Stephen Powell)