U.S. forces launched airstrikes in Iraq on Thursday against Iranian-backed Shia militia members believed to be behind a rocket attack that killed and wounded American and British troops at Iraq’s Camp Taji, the Pentagon confirmed Thursday. According to The Washington Post, the Defense Department said the strikes were “defensive, proportional, and in direct response to the threat” posed by the militia members. “The United States will not tolerate attacks against our people, our interests, or our allies,” Defense Secretary Mark Esper said in a statement. “As we have demonstrated in recent months, we will take any action necessary to protect our forces in Iraq and the region.” According to The Associated Press, one official said the multiple strikes—a joint operation with the U.K.—targeted Kataib Hezbollah weapons facilities in Iraq. This comes after two Americans and one other coalition member were killed and 12 were wounded in the Wednesday night attack against Camp Taji, which was reportedly hit by 18 Katyusha rockets.