Rockets strike western Iraq base hosting US troops
No casualties were reported when the missiles struck Ain al-Asad, which hosts US troops serving in Anbar province.
The US currently has 5,200 troops in Iraq, part of a US-led international coalition against the Islamic State group.
Their presence at several bases in Iraq has been the subject of debate, with pro-Iranian Shia militias and politicians making frequent demands for their withdrawal.
In October, US Defence Secretary Mark Esper said American troops withdrawing from Syria would stay in Iraq "temporarily" before returning to the US.
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The troops have been targeted in mystery strikes on several occasions in the past few months.
Most recently, at least 17 rockets struck a military base north of the Iraqi capital where US troops are deployed, Iraqi security source said on 9 November.
Iraqi commander of operations Noman Zobaei said forces responded to the attack in a strike that "killed three terrorists and destroyed a vehicle".
A second vehicle loaded with another missile was seized from the scene of the operation, according to local Alsumaria TV.
It is unknown who is responsible for the attacks, however several mystery strikes have also targeted Iraq's Popular Mobilisation Forces (PMF) - a coalition of some 70, mostly Shia militias backed by Iran - in recent months.
The PMF have repeatedly blamed Israel for being behind the strikes.