Seven mortar bombs have hit the Iraqi Balad Air Base in the north of the country, Reuters quoted military sources as saying. According to sources, four Iraqi soldiers were injured in the incident.
However, AFP cited security forces as saying that the base was hit by just four rockets.
The military installation is an Iraqi Air Force Base situated some 64 kilometres north of the capital Baghdad. The majority of US troops have withdrawn from the base amid rising US-Iranian tensions in recent weeks.
On 4 January, the base came under a rocket attack in the wake of Iranian top military commander Soleimani's killing by US forces.
Last week, Iraq's parliament voted to expel US troops from the country and to put a formal end to Iraq's participation in the US-led anti-Daesh* coalition.
* Daesh (ISIL/ISIS/IS/Islamic State) is a terrorist organisation banned in Russia