U.S. officials say retaliatory air strikes were conducted against an Iran-backed militia group operating in Iraq following a deadly attack a day earlier against a base hosting Western forces near Baghdad.
One U.S. official told AP late on March 12 that multiple strikes targeted Kataib Hezbollah weapons sites inside Iraq.
The official said the strikes were a joint U.S.-British operation and that they were still ongoing when he spoke with AP.
U.S. Defense Secretary Mike Esper earlier blamed Iran-backed Shi'ite militia groups for the attack on the coalition at the Camp Taji military base, located less than 30 kilometers north of Baghdad.
He said that "all options are on the table" as Washington and its allies try to bring those responsible for the attack, which killed two U.S. troops and one British soldier and wounded a dozen others when a barrage of Katyusha rockets were launched from a truck later discovered several kilometers from Camp Taji.
The latest action came hours after the British-based Syrian Observatory for Human Rights said air strikes in eastern Syria killed 26 fighters from an Iran-backed Iraqi paramilitary group near the Syrian border town of Albu Kamal and that they were probably carried out by the U.S.-led coalition.
U.S. officials did not confirm if their forces were involved in the Syria attack, but in December U.S. launched air strikes against Iraqi militia targets on Syria border.