"Blasts occurred in a base belonging to the Hashed al-Shaabi" in Babylon province, the security source said, referring to an alliance of pro-Iranian former paramilitary groups now integrated into the regular army.

"The cause of the blasts was not immediately known," the source added, but a Hashed official said an "airstrike" hit the base.

On July 18, an explosion hit "logistics" warehouses belonging to Hashed south of Baghdad, and in April, one person was killed and eight wounded in a blast at a military base housing Hashed groups in Babylon province.

Hashed al-Shaabi is an integral part of the Iraqi security apparatus under the authority of the prime minister.

It includes some pro-Iran groups that have carried out dozens of attacks against US forces in Iraq and neighbouring Syria.