Three people have been killed after a base hosting US and UK troops in Iraq was hit by a rocket attack, the BBC reports.
At least 12 people were injured in the attack on the Taji military camp, north of Baghdad.
US military sources said an American soldier, an American contractor and a British soldier were killed. No names have yet been released.
Tension has been high since the US killed senior Iranian commander Qasem Soleimani in a drone strike in January.
A retaliatory Iranian strike on al-Asad - another base hosting US troops - on 8 January left more than 100 soldiers suffering from traumatic brain injuries (TBI).
However, both Iran and the US appeared then to want to draw a line under the matter and there have been no major flare-ups since.
Tensions between the arch-foes intensified last year, after Iran-backed militia fighters targeted US military and civilian personnel in a series of rocket attacks. There were also unclaimed air strikes in Iraq targeting militia facilities and Iranian officials.
In late December, a rocket attack on an Iraqi military base killed a US civilian contractor.
The US blamed the powerful Kataib Hezbollah militia, which is part of the paramilitary Popular Mobilisation force. It carried out air strikes on its bases in western Iraq and eastern Syria that left at least 25 fighters dead.
