Air strikes killed at least nine Iran-backed fighters in Iraq on Thursday near the Iraqi-Syrian border, two senior security officials told AFP.
Another 10 fighters were wounded in the strikes that targeted a base belonging to the US-blacklisted Harakat Ansar Allah al-Awfiya, the officials added on condition of anonymity, with one saying that the death toll could rise.
"The base was destroyed, and the rescue teams who arrived at the site were also targeted," one of the officials said.
He added that it remained unclear who was behind the attack. But the Iran-backed faction said in a statement that a "Zionist-American aggression" targeted their fighters, though it did not provide a death toll.
Iraq has long been a proxy battleground between the United States and Iran, with the country's successive governments struggling to balance relations between the two rivals.
After decades of conflicts, it had recently regained some stability, but it remains volatile with increasingly influential armed groups operating outside the state's control.
Iraq was immediately dragged into the Middle East war triggered when the United States and Israel attacked Iran on February 28.
The base that was hit on Thursday belongs to the Hashed al-Shaabi or the Popular Mobilization Forces (PMF), a former paramilitary group now integrated into the regular army.
The Hashed also encompasses brigades from Iran-backed groups, which have been repeatedly targeted in attacks blamed on the United States and Israel since the start of the war.
The contingent on the base is made up of members of Harakat Ansar Allah al-Awfiya.
Iraq's national security advisor Qassem al-Araji mourned in a post on X dozens "of martyrs and wounded" from the Hashed forces in what he described as a "terrorist attack".
