AMMAN - US-backed Syrian rebels were forced to retreat from the outskirts of an Islamic State-held town at the border with Iraq and a nearby air base on Wednesday after a counter attack by the jihadists, two rebel sources said.The US-backed New Syria Army rebel group had launched the attack aiming to capture the town of Al-Bukamal on Tuesday.One of the rebel sources said Islamic State fighters had encircled the rebels in a surprise ambush. The rebels had incurred heavy casualties and weapons had been seized by the jihadists, the source said.A spokesman of the New Syria Army, Muzahem al Saloum, confirmed they had retreated. "We have withdrawn to the outlying desert and the first stage of the campaign had ended," Saloum told Reuters.
