Defence Secretary Lloyd Austin said the strikes were carried out on three facilities used by the Iranian-backed Kataib Hezbollah militia group and other Iran-affiliated groups in Iraq.

"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," he said.

The US Central Command said in a statement: "In response to attacks by the Iranian-backed militia group Kataib Hezbollah (KH), including the attack on al-Asad Airbase in western Iraq on Jan. 20, on Jan. 24 at 12:15 a.m., U.S. CENTCOM forces conducted unilateral airstrikes against three facilities used by Iranian-backed Kataib Hezbollah militia group and other Iran-affiliated groups in Iraq."

"These strikes targeted KH headquarters, storage, and training locations for rocket, missile, and one-way attack UAV capabilities," the statement said.

Austin said: "I am grateful for both the skill and professionalism with which our personnel planned and conducted these strikes and the continued efforts of our troops on the ground as they work with regional partners to further dismantle and degrade ISIS."

Jafar al-Hussaini, the military spokesman for Kataib Hezbollah, wrote on X as quoted by CNN that the group will “continue to strike the strongholds of the enemies, in support of our people in Gaza until the brutal killing machine backed by America stops, and the complete siege is lifted. This is the promise of the free people.”

The latest strikes were conducted just days after  US personnel at  Al-Asad Air Base in Iraq were injured in rocket and ballistic missile attacks.

Giving details about the attack, US Central Command earlier posted on X: " Most of the missiles were intercepted by the base’s air defense systems while others impacted on the base. Damage assessments are ongoing. A number of U.S. personnel are undergoing evaluation for traumatic brain injuries. At least one Iraqi service member was wounded."

The initial assessment is that Kataib Hezbollah was responsible for the ballistic missile attack, a defence official told CNN