Injuries and “material losses” have been reported after a large explosion at a military base in Iraq.
The cause of the blast – at the Kalsu facility in the city of Babylon – is currently unconfirmed
However, two security sources told the Reuters news agency an air strike from an unknown source was to blame.
A US official said it wasn’t caused by American military operations.
The base is used by Iraq’s Popular Mobilization Forces (PMF), an umbrella group of dozens of armed groups, and is home to its chief of staff.
One PMF fighter was killed and six were wounded, according to sources at the nearby hospital in Hilla.
The group did not confirm any deaths in its initial statement.
It said: “An explosion occurred at the headquarters of the Popular Mobilization Forces at the Kalsu military base in the Al-Mashrou district on the highway, north of Babil Governorate.
“An investigation team immediately arrived at the scene, and the explosion caused material losses and injuries. We will provide you with the details once the preliminary investigation is completed.”
Footage from a car shows a fire in the distance followed by a large explosion that appears to launch bright fragments into the sky.
The base is about 30 miles (50km) south of Iraqi capital Baghdad.
Pics: Popular Mobilization Forces of Iraq
The explosion comes a day after Israel hit back at Iran, with air defences launched from an Iranian airbase and a nuclear site near the city of Isfahan.
Three drones were reportedly hit but there were no reports of damage or casualties.
It followed last week’s unprecedented drone and missile attack on Israel by Iran – itself retaliation for a strike on an Iranian consulate in Syria.