(A fighter from the Islamic State, formerly known as the Islamic State of Iraq and the Levant (ISIL), mans an anti-aircraft gun mounted on the rear of a vehicle in Mosul July 16, 2014. The Iraqi army and allied Shi'ite militia forces are trying to push back the Sunni insurgents of the al Qaeda offshoot, who swept through northern Iraq last month to within 70 km (45 miles) of Baghdad. The banner on the bridge reads: "Welcome to the State of Nineveh; There is no God but God and Mohammad is the Messenger of God". Picture taken July 16, 2014. REUTERS/Stringer )

(A fighter from the Islamic State, formerly known as the Islamic State of Iraq and the Levant (ISIL), mans an anti-aircraft gun mounted on the rear of a vehicle in Mosul July 16, 2014. REUTERS/Stringer )