At least five people have been killed in an explosion at an arms depot in southern Iraq, the national news agency said on Monday.
The blast occurred at a military base outside Najaf run by Saraya Al Salam, a militia run by supporters of Moqtada Al Sadr.
Explosions at weapons stores are common in Iraq during the summer, when temperatures regularly exceed 40°C. High explosives become volatile in extreme heat and rapid changes in temperature cause components to expand under pressure, making them more dangerous to handle.
Blasts at the height of Iraq's summer have previously hit storage sites belonging to militias of various loyalties, including pro-US Kurdish Peshmerga forces and armed groups backed by Iran.
A series of explosions at arms depots run by Iran-backed Iraqi militias in the summer of 2019 led Popular Mobilisation Forces leader Abu Mahdi Al Muhandis to blame the US and Israel for targeting their warehouses with drones.
His forces subsequently stepped up attacks on the US-led coalition in Iraq, leading to the death of a US contractor. A series of retaliatory air strikes later killed Al Muhandis and Iranian Maj Gen Qassem Suleimani near Baghdad Airport in January 2020, an escalation that brought Iran and the US to the brink of war.