A new U.S. strike on a base in western Iraq killed seven security personnel, the Defense Ministry said Wednesday, a day after a deadly attack on the same facility targeted the former paramilitary Hashed al-Shaabi.

Iraq has been unwillingly pulled into the war sparked by U.S. and Israeli strikes against Iran on Feb. 28 and which has since engulfed much of the region.

Pro-Iran armed groups have claimed responsibility for attacks on U.S. interests in Iraq and across the region, while strikes have also targeted these groups, including on state-linked positions.

The Defense Ministry said seven security personnel were killed and 13 others wounded in the attack on the base in Anbar province, which hosts both regular security personnel and Hashed forces.

The ministry said the airstrike also targeted the base's military health care clinic.

It labelled the assault a "flagrant and dangerous violation of international law, which prohibits targeting medical facilities and their personnel."

Rescue operations were ongoing, it added.

A security official told Agence France-Presse (AFP) that a military doctor was among those killed and six of those wounded belonged to the Hashed al-Shaabi, also known as the Popular Mobilization Force (PMF).

It follows Tuesday's strike on the same base, which was the deadliest in Iraq since the start of the war, killing 15 PMF fighters, including a commander.

The PMF – now part of Iraq's regular armed forces, but also including brigades belonging to Iran-backed groups – blamed that strike on the U.S.

The coalition was formed in 2014 to help fight the Daesh terrorist group, but has since been integrated into the armed forces, though some of its factions have been known to act independently of the state.

Tuesday's attack prompted the government to grant the PMF and groups within the official armed forces the "right to respond" to any attack by drones or aircraft against their bases

The decision was backed by the Coordination Framework, Iraq's ruling coalition of Shiite parties with varying links to Iran, which said the government retained "the exclusive right of the state over decisions of war."

The Pentagon has acknowledged that combat helicopters carried out strikes against pro-Iran armed groups in Iraq during the current conflict.

Baghdad has condemned attacks targeting foreign soldiers and diplomatic missions, as well as strikes against PMF positions.

Throughout Tuesday evening and into Wednesday morning, the sounds of military aircraft flying over the capital Baghdad were particularly loud, AFP journalists reported.