A huge explosion rocked an Iraqi military base early Saturday, killing a member of the Iraqi security forces, which includes Iran-backed groups. Force commanders called it an attack, while the military said it was investigating and that there were no warplanes in the sky at the time.

Two security sources earlier said the blast was caused by an airstrike and killed one member of the Iraqi Popular Mobilization Forces (PMF) and another at the Qalso military base, about 50 kilometers (30 miles) south of Baghdad. Eight people were injured.

The PMF said in a statement that its chief of staff Abdul Aziz Mohammed had visited the site and “reviewed details of the commission of inquiry into the site of the attack”.

The Iraqi military said a technical committee was investigating the cause of the explosion and fire at the base, which it said occurred at 1am on Saturday (2200 GMT on Friday).

“The Air Defense Command report confirmed through technical efforts and radar detection that there were no drones or fighter jets in Babylonian airspace before and during the explosion,” the military said in a statement.

The incident in Iraq’s Babylon province comes as tensions in the Middle East are running higher than usual, with sources saying that Israel launched an attack on the Iranian city of Isfahan on Friday. Tehran played down the incident and said it had no plans to retaliate.

The incident came six days after Iran launched a barrage of missiles and drones into Israel in response to an alleged Israeli airstrike that destroyed part of the Iranian embassy in Damascus and killed seven people on April 1 Iranian Revolutionary Guards officer.

The PMF includes Iran-backed groups that, under the banner of Iraq’s Islamic Resistance Movement, have attacked U.S. forces in the region since the war in Gaza began and targeted Israel, claiming to support the Palestinians.

They halted attacks on U.S. troops in Syria and Iraq after a drone strike in Jordan killed three U.S. soldiers in early February, prompting heavy U.S. airstrikes in Iraq and Syria.
But they claimed responsibility for an attack in the Israeli city of Eilat on April 1.

Earlier on Saturday, U.S. Central Command posted on X denying reports of U.S. air strikes in Iraq. “The United States did not conduct air strikes in Iraq today,” the statement said.

The PMF began as a group of armed factions, many with close ties to Iran, and was later recognized by Iraqi authorities as a formal security force.