An attack by an unmanned aerial surveillance system on Saturday targeted Iraq's Ain al-Asad air base in western Iraq which hosts US and other international forces, but it caused no injuries, a coalition spokesman said.
US Army Colonel Wayne Marotto, spokesman for the US-led coalition, said on Twitter that the attack was being investigated but that an initial report suggests that the attack took place at 0220 local time and caused damage to a hangar.
The United States accuses Iran-backed militia groups of launching regular rocket attacks against its troops in Iraq.
There was no immediate claim of responsibility for Saturday's attack.
