Three U.S. service members were injured in Iraq on Christmas Day when Kataib Hezbollah terrorists attacked Erbil Air Base, according to Secretary of Defense Lloyd J. Austin.

Austin announced late on Monday night that American forces "conducted necessary and proportionate strikes on three facilities used by Kataib Hezbollah and affiliated groups in Iraq."

"These precision strikes are a response to a series of attacks against U.S. personnel in Iraq and Syria by Iranian-sponsored militias, including an attack by Iran-affiliated Kataib Hezbollah and affiliated groups on Erbil Air Base earlier today, and intended to disrupt and degrade capabilities of the Iran-aligned militia groups directly responsible," Austin said in a press release.

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Erbil airbase exteriors

A US military base established in Herir District, 70km from Erbil, is seen in Iraq in 2015.  (Photo by Hamit Huseyin/Anadolu Agency/Getty Images/File)

"Today’s attack led to three injuries to U.S. personnel, leaving one service member in critical condition," the statement added. "My prayers are with the brave Americans who were injured."

This story is developing. Check back with us for more updates.