Two Iraqi military bases were bombed after midnight on Saturday by unknown aircraft in Babil Province, south of Baghdad, Xinhua News Agency reported citing an Interior Ministry source.

The airstrikes were carried out by drones and targeted two bases belonging to Iraqi paramilitary group Hashd al-Shaabi in the Mahawil area, in the northern part of Babil province, the source said.

One of the targets was an ammunition warehouse of Hashd al-Shaabi and the other was a tank garage.

An AFP report said the bombing killed one person and injured eight others at the Kalsu military base in Babil, while Reuters reported that one person was killed and six more were wounded.

In a statement, Hashd al-Shaabi confirmed an explosion occurred and had inflicted material losses and casualties. It did not specify the number of wounded or whether it had been a drone strike, noting that investigations are ongoing. 

There was no immediate claim of responsibility for the attack and the U.S. has swiftly denied it was behind the airstrike.

"We are aware of reports claiming that the United States conducted airstrikes in Iraq today. Those reports are not true. The United States has not conducted air strikes in Iraq today," the U.S. Central Command said on social media.

(With input from agencies)