The U.S. military carried out strikes on Iran-backed targets in Iraq on Tuesday, Secretary of Defense Lloyd Austin said, retaliating against a series of Iranian-backed attacks against the U.S. in the region.

“Today, at President Biden’s direction, U.S. military forces conducted necessary and proportionate strikes on three facilities used by the Iranian-backed Kataib Hezbollah militia group and other Iran-affiliated groups in Iraq,” Austin said in a statement Tuesday evening. “These precision strikes are in direct response to a series of escalatory attacks against U.S. and coalition personnel in Iraq and Syria by Iranian-sponsored militias.”

U.S. and Iraqi troops were injured Saturday in a missile attack on a base in western Iraq, leaving some Americans in need of evaluation for traumatic brain injuries, U.S. Central Command said over the weekend.

Tuesday’s strikes targeted three facilities used by the Kataib Hezbollah militia group, including the group’s headquarters, storage and training locations for rocket, missile and one-way attack UAV capabilities, according to U.S. Central Command.

“We do not seek to escalate conflict in the region. We are fully prepared to take further measures to protect our people and our facilities,” Austin’s statement said.