The government of Syrian President Bashar al-Assad and
rebels who have been fighting to oust him accuse each other of
using chemical weapons in Aleppo in March and Homs in December.

“The Secretary-General (Ban Ki-moon) remains gravely
concerned about the allegations of the use of chemical weapons,”
Robert Serry, the U.N. Middle East peace envoy, told the U.N.
Security Council.

“Amid mounting reports on the use of chemical weapons, we
once again urge the government of Syria to allow the
investigation to proceed without further delay,” he said.

A team of U.N.-led chemical weapons experts has been ready
for more than a month to enter Syria to investigate the
allegations, but has been held up by diplomatic wrangling and
safety concerns.

U.N. Secretary-General Ban Ki-moon has urged Syria to give
the experts unfettered access to investigate all alleged
chemical arms incidents. But Assad’s government only wants the
U.N. team to probe the Aleppo attack, not Homs. U.N. diplomats
say U.N.-Syria negotiations on access have reached a deadlock.

A senior Western diplomat said on condition of anonymity
that there have been “new incidents” of chemical weapon use by
Assad’s government since April. He declined to elaborate.

Syrian U.N. Ambassador Bashar Ja’afari did not respond
immediately to a request for comment.

U.N. officials and diplomats say that the U.N. team, which
is headed by Swedish scientist Ake Sellstrom, is working outside
Syria to gather information about possible chemical weapons use.

“The mission (Ban) established to investigate the claims has
been doing what it can to gather and analyze available
information,” Serry said.

HUMANITARIAN CRISIS

Earlier this month, Carla Del Ponte, a member of a U.N.
inquiry commission looking at allegations of war crimes in
Syria, said the commission had gathered testimony from
casualties and medical staff indicating that rebel forces had
used the banned nerve agent sarin.

But the commission, which is separate from Sellstrom’s
chemical weapons investigation team, quickly issued a statement
distancing itself from Del Ponte’s remarks, saying it has
reached no conclusions on whether any side in the Syrian war has
used chemical weapons.

Syria, which is not a member of the anti-chemical weapons
convention, is believed to have one of the world’s last
remaining stockpiles of undeclared chemical arms.

Serry also spoke of the worsening humanitarian crisis in
Syria, where the United Nations believes at least 80,000 people
have died since the uprising began in March 2011.

“The Secretary-General remains deeply alarmed at the
escalating violence in Syria,” he said. “The humanitarian crisis
continues to worsen, with every third Syrian now in need of
urgent assistance. One of every four has been uprooted from her
or his home.”

Serry reiterated U.N. hopes a U.S.-Russian push for a peace
conference in Geneva including both sides in the conflict will
be successful, adding that the world body is “fully devoted to
helping the Syrians find a political solution.” Expectations of
a breakthrough are low.

Russia, backed by China, has refused to consider sanctions
on Assad’s government, vetoing three U.N. Security Council
resolutions condemning his onslaught against the opposition.

(Editing by Doina Chiacu)