The U.S. military carried out retaliatory precision air strikes on Monday in Iraq after a one-way drone attack earlier in the day by Iran-aligned militants that left one U.S. service member in critical condition and wounded two other U.S. personnel, officials said.

At President Joe Biden’s direction, the U.S. military carried out the strikes at 1:45 GMT, likely killing “a number of Kataib Hezbollah militants” and destroying multiple facilities used by the group.

“These strikes are intended to hold accountable those elements directly responsible for attacks on coalition forces in Iraq and Syria and degrade their ability to continue attacks. We will always protect our forces,” said General Michael Erik Kurilla, head of U.S. Central Command, in a statement.

A U.S. base in Iraq’s Erbil that houses U.S. forces came under attack from a one-way drone earlier on Monday, leading to the U.S. casualties.

The Pentagon did not disclose details about the identity of the service member who was critically wounded or offer more details on the injuries sustained in the attack.

“My prayers are with the brave Americans who were injured,” U.S. Defense Secretary Lloyd Austin said in a statement.

The White House National Security Council said Biden was briefed on the attack on Monday morning and ordered the Pentagon to prepare response options against those responsible.

“The President places no higher priority than the protection of American personnel serving in harm’s way. The United States will act at a time and in a manner of our choosing should these attacks continue,” NSC spokesperson Adrienne Watson said.

Monday’s military attack and U.S. retaliation is the latest back-and-forth since a surge in violence began in mid-October, when Iran-aligned militias started targeting U.S. assets in Iraq and Syria over Washington’s backing of Israel in its war against Hamas in Gaza.