Kurdish authorities imposed a curfew in parts of Deir Ezzor province in eastern Syria after deadly clashes erupted over the capture of the leader of a local Arab armed group.

Last Sunday the Syrian Democratic Forces (SDF), a coalition dominated by Syrian Kurds, arrested Ahmad al-Habil, the leader of the Deir Ezzor Military Council. It is a local, Arab organization that was working with the SDF.

After al-Habil’s capture, clashes erupted in Kurdish-controlled areas of the province between SDF and Military Council fighters. According to the Syrian Observatory for Human Rights, at least 54 people were killed, six of whom were civilians.

“The Deir Ezzor Military Council and (Kurdish) internal security forces announce a curfew from 5 am on September 2 for 48 hours,” the SDF said in a statement. The SDF accused armed groups linked to the Syrian regime’s security services as well as elements of the jihadist Islamic State group of trying to “stir up unrest” in the region.

According to Rami Abdel Rahman, the head of the Observatory, Arab fighters backed by Iran (which is an ally of Damascus) took advantage of the clashes to move from a part of the province controlled by the Syrian regime to two villages controlled by the Kurds. They were the ones who clashed with Kurdish forces after a video of their leader calling on Arab tribes to turn against the Kurds was released.

Earlier yesterday, the US military’s Middle East Command (Centcom) said “the violence in northeastern Syria must stop” and reiterated US support for the SDF. The fighting took place near the Conoco gas field, where there are bases of the international anti-jihadist coalition, the largest of which is the American one.

The reasons for al-Habil’s arrest have not been clarified, but the Observatory and a local activist told AFP that he was known to be involved in smuggling.