The U.S. military said Monday it had captured an operator for the Islamic State extremist group during a helicopter raid in northern Syria.

The operator, Abu Halil al-Fad’ani, “was assessed to have relationships throughout the ISIS network in the region,” U.S. Central Command said in a statement.

His capture on Saturday increases the chance that U.S. counterterrorism operations there will be able to target additional members of the group, command spokesman Lt. Col. Troy Garlock said.

The U.S. has approximately 900 troops in Syria focused on countering the remnants of the Islamic State group, which had held a wide swath of Syria until 2019.

News of the capture came as U.S.-backed Kurdish-led forces imposed a curfew after continued skirmishes with rival Arab militiamen. According to reports from Syrian media and activists, the Syrian Democratic Forces imposed the curfew Monday in several towns in Deir el-Zour province, including in Ziban, close to the Iraqi border where the Americans are based. Hundreds of U.S. troops have been there since 2015. The oil-rich province has Syria’s largest oil fields.

Syria remains in a bloody 12-year civil war that has killed a half-million people. The Syrian government of President Bashar Assad in Damascus sees the Kurdish-led forces as secessionist fighters and has denounced their alliance with the United States in the war against the Islamic State militants and their self-ruled enclave in eastern Syria.