The bombing targeted a base in Anbar province during a commanders' meeting, a source from the group told AFP on condition of anonymity, blaming the United States for the attack.

Seven Hashed al-Shaabi fighters were "killed and 13 wounded in a US strike", the source added.

Hashed al-Shaabi, also known as the Popular Mobilisation Forces (PMF), is part of Iraq's regular armed forces but also includes some brigades belonging to Iran-backed groups.

A PMF statement condemned the strike, which it said killed the provincial commander and head of operations in Anbar, Saad Dawai al-Baiji, as well as several fighters, but did not give further details.

A security official told AFP that the wounded were being treated at a hospital.

Iraq has been unwillingly pulled into the war triggered by Israel and the United States striking Iran on February 28.

Pro-Iran armed groups have claimed responsibility for attacks on US interests in Iraq and across the region, while strikes have also targeted these groups.

Since the start of the conflict, Baghdad has repeatedly denounced attacks on the Hashed al-Shaabi.

Last week, the Pentagon acknowledged for the first time that combat helicopters had carried out strikes against pro-Iran armed groups in Iraq during the latest conflict.