According to the US defence department "the strikes targeted five weapons storage facilities across the country belonging to Kata’ib Hezbollah."

Two Americans and a British soldier were killed in Wednesday's rocket attack on the Camp Taji military base.

Earlier, a US commander said an Iranian-backed militia group was likely to have fired the rockets.

In a statement on Thursday night, the defence department confirmed that a series of "defensive precision strikes" were carried out by manned aircraft against Kataib Hezbollah facilities.

"These include facilities that housed weapons used to target US and coalition troops," it said. "[The strikes] were defensive, proportional, and in direct response to the threat posed by Iranian-backed Shia militia groups."