Several U.S. military personnel were injured in a missile attack Saturday night by Iranian-backed rebels on Al-Asad Airbase in Iraq, the Pentagon said.

At about 6:30 p.m. local time, multiple ballistic missiles and rockets were fired by Iranian-backed militants from western Iraq, U.S. Central Command said in a statement posted to social media.

The base’s air defense systems intercepted “most of the missiles,” but “others impacted the base,” CENTCOM reported.

Multiple U.S. personnel were being evaluated for traumatic brain injuries, CENTCOM said, and at least one Iraqi soldier was also wounded. No further details were immediately provided.