Fourteen rockets were fired Wednesday at the Ain al-Assad air base which hosts American troops in western Iraq, a spokesman for the US-led coalition said.

The base was attacked by 14 rockets that "landed on the base & perimeter... At this time initial reports indicate 3 minor injuries. Damage is being assessed," Colonel Wayne Marotto wrote on Twitter.

It was the latest in a spate of attacks targeting US military and diplomatic facilities in Iraq that have been blamed on pro-Iranian armed groups within a state-sponsored paramilitary force.

US forces, whose 2,500 troops are deployed in Iraq as part of an international coalition to fight the jihadist Islamic State group, have been targeted almost 50 times this year.