BEIRUT (AP) - An explosion struck Wednesday near a patrol of the U.S.-led coalition in the northern Syrian town of Manbij, killing and wounding more than a dozen people, a Syrian war monitoring group and a local town council said.
The Britain-based Syrian Observatory for Human Rights said 16 people were killed including nine civilians and others were wounded in the blast. It added that at least five U.S.-backed Syrian fighters were also among the dead.
The rare attack came days after the U.S. began the process of withdrawing from Syria, pulling out equipment from the northeast into neighboring Iraq.
There was no immediate comment from the U.S.-led coalition on whether there were casualties among coalition forces.
U.S. military Col. Sean Ryan said they were "aware of open source reports regarding an explosion in Syria. Coalition forces conducted a routine patrol in Syria today. We are still gathering information and will share additional details at a later time."
Videos released by local activists and news agencies showed a restaurant that suffered extensive damage and a street covered with debris and blood. Several cars were also damaged. Another video showed a helicopter flying over the area.
The Kurdish Hawar news agency, based in northern Syria, and the Observatory, which monitors the war through activists on the ground, reported U.S. troops were among the casualties.
Turkey's state-run Anadolu Agency, citing unnamed local sources, said a number of U.S. soldiers were injured in the blast and that the U.S. military evacuated soldiers by helicopter.
The Islamic State group claimed responsibility for the blast, saying one of its members carried out a suicide attack and detonated his vest with explosives.
The Observatory and the Kurdish-led Manbij Military Council, which runs the town, said the blast occurred near a restaurant near the town's main market.
The Observatory's chief Rami Abdurahman also said the explosion was caused by a suicide bomber but didn't immediately have any further details.
It was not the first time that forces of the U.S.-led coalition were subjected to attacks in the area, although they have been rare.
In March last year, a roadside bomb killed two coalition personnel, an American and a Briton, and wounded five in Manbij.