The U.S. announced May 31 that it killed three militants in a Somalia airstrike. Officials now say the target was ISIS leader Abdulqadir Mumin, but also say they aren’t certain he is dead.

The U.S. military targeted the global leader of ISIS in an airstrike in Somalia late last month but cannot confirm whether he was killed, three U.S. officials say.

The U.S. government has publicly identified Abdulqadir Mumin as the head of the ISIS affiliate in Somalia, but two U.S. officials say that last year he quietly became the worldwide leader of the terror group.

U.S. Africa Command released a statement on May 31 saying it had conducted an airstrike against ISIS militants in a remote area 81 km (50 miles) southeast of Bosaso, Somalia, and killed three militants. The AFRICOM statement did not say whom the U.S. was targeting, however, or who was killed. AFRICOM reported that no civilians were killed in the strike.