U.S. forces carried out strikes Monday targeting Iran-backed militias in Iraq in response to a drone attack that injured three U.S. service members.

The U.S. strikes were directed at three locations used by Kataib Hezbollah and affiliated groups, Defense Secretary Lloyd Austin said in a statement.

“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.”

National Security Council spokesperson Adrienne Watson said Kataib Hezbollah, as part of an umbrella group of Iran-backed militants, claimed credit for the Monday attack and that one of the U.S. service members was critically hurt.

U.S. and coalition forces have operated in the region as part of the mission to counter the Islamic State group in Iraq and Syria.

Those forces have come under repeated attacks by Iranian-backed proxies, with about 100 attacks coming since Israel launched its offensive to eliminate the militant group Hamas in the Gaza Strip.

The U.S. military has said it disrupted most of those attacks, or that they fell short of their targets causing no damage. But several, like Monday’s, have injured U.S. military personnel.

Previous retaliatory strikes have targeted Kataib Hezbollah and other groups, including U.S. strikes in November.

Carla Babb contributed to this report.