A drone attack by an Iran-affiliated terrorist group on a military base in Iraq early Monday morning left three U.S. service members wounded, the Pentagon said, and prompted President Biden to order retaliatory strikes.  

The attack on the Erbil Air Base in northern Iraq was conducted by Kataib Hezbollah militants, Defense Secretary Lloyd Austin said in a statement. One of the three service members wounded is in critical condition, Austin disclosed.

In response, Mr. Biden — after being briefed and holding a call with Austin and his national security team — ordered retaliatory strikes on "three locations utilized by Kataib Hezbollah and affiliated groups focused specifically on unmanned aerial drone activities," National Security Council spokesperson Adrienne Watson said in a statement.

According to U.S. Central Command, the retaliatory strikes on the three sites, all located in Iraq, were conducted at 8:45 p.m. Eastern Time and "likely killed a number of Kataib Hezbollah militants." 

No civilians were believed to have been wounded or killed, CENTCOM said.

Iraqi officials said the U.S. strikes killed one militant and injured 18, the Associated Press reports.

In a statement, Iraqi Prime Minister Mohammed Shia al-Sudani condemned both the militia attack and the U.S. response, calling the U.S. strikes a "hostile act" that infringed on Iraqi sovereignty, the AP reported.

There have been dozens of attacks by Iranian-backed militias targeting U.S. forces in Iraq and Syria since the violent Oct. 7 terrorist assault on Israel by Hamas — a group that U.S. officials have long said receives financial and material support from Iran.  

In response, U.S. forces have conducted several rounds of strikes on what defense officials say are Iran-linked weapons facilities and Iran-backed fighters. 

On Nov. 20, several U.S. service members were injured in a ballistic missile attack by Iran-backed militias on Al-Asad Airbase in Iraq, the Pentagon said. In similar fashion to Monday's retaliation, the U.S. immediately launched strikes on militia-linked facilities and personnel. 

This also comes as Iranian-linked Houthi rebels in Yemen have also been conducting numerous attacks on commercial vessels in the Red Sea. Last week, the White House accused Iran of being "deeply involved" in those Red Sea attacks, an allegation Tehran denied. 

In a Nov. 15 interview with CBS News, Iranian Foreign Minister Hossein Amir-Abdollahian denied that Iran was responsible for a drone fired from Yemen that was shot down by the guided-missile destroyer USS Thomas Hudner. The drone appeared to be targeting the Hudner, U.S. officials said at the time.

"We really didn't want this crisis to expand," Amir-Abdollahian told CBS News, referencing the Israel-Hamas war. "But the U.S. has been intensifying the war in Gaza by throwing its support behind Israel. Yemen makes its own decisions and acts independently." 

Last week, energy giant BP announced it was temporarily suspending all gas and oil shipments in the Red Sea because of the attacks. 

—David Martin, Eleanor Watson, S. Dev, Arden Farhi, Olivia Gazis and Brian Dakss contributed to this report. 

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• Iraq
• Drone

Faris Tanyos is a news editor for CBSNews.com, where he writes and edits stories and tracks breaking news. He previously worked as a digital news producer at several local news stations up and down the West Coast.