A U.S. military service member has been killed in combat in northern Iraq, the Associated Press reports. The American, serving as an advisor to Kurdish Peshmerga troops, was killed by “direct fire” from Islamic State forces that had breached the Peshmerga’s forward line.

U.S. defense officials said one American soldier was killed Thursday morning as Special Forces and Iraqi troops raided an ISIS-run prison in northern Iraq, the first U.S. soldier killed in action in Iraq since 2011.

Kurdish authorities in Iraq say that ISIS used chemical weapons in a January 23 suicide attack against peshmerga fighters, the Associated Press reports.