BEIRUT — The Islamic State on Sunday repelled an advance by US-backed forces on one of its main bastions in northern Syria, seizing back territory it had previously lost, Syrian activists and the extremist group said.
The group, also known as ISIS, said its fighters infiltrated villages and mountains near the town of Manbij that were seized last month by the Syrian Democratic Forces, a Kurdish-dominated group aided by US Special Forces.
In a statement carried by the militant-run Aamaq news agency, the group said a fighter driving a car packed with explosives struck a gathering of Kurds amid clashes in the northwestern part of Manbij.
Manbij, which is on a key supply line from Turkey to the group’s de facto capital of Raqqa, has been encircled by the SDF for weeks.
The Syrian Observatory for Human Rights also reported the ISIS counteroffensive. The Britain-based group, which relies on a network of activists on the ground, reported heavy clashes accompanied by US-led airstrikes.
Also Sunday, the Syrian Arab Red Crescent said that its convoy came under fire while on its way back from delivering humanitarian aid to a rebel-held suburb of Damascus, the Syrian capital, and that one of its staffers was ‘‘hit.’’