An Iraqi army soldier stand guard near a US-made Iraqi Air Force F-16 fighter jet at the Balad Air Base, Iraq, on February 13, 2018. (Photo: Khalid Mohammed/AP)

A statement by the media office affiliated with the Iraqi Joint Operations Command said that eight Katyusha rockets struck the airbase, which previously housed US troops and is located about 90 km north of Baghdad.

Balad is the largest military air base in Iraq. It was housing US troops and advisors of a US company operating the Iraqi F-16 jet fighters, but they withdrew about a week ago after the US-led coalition announced the suspension of its operations against Islamic State militants in Iraq.

No group has so far claimed responsibility for the attack, which came a few days after Qais al-Khazali, leader of the Iraqi Shiite militia Asa'ib Ahl al-Haq, said the initial Iranian response to the killing of an Iranian military leader is finished and it is time for Iraq to respond to the US airstrike.