The US military has confirmed its planes made an attack on an Islamic State-held area in Mosul, Iraq, where residents and officials say dozens of civilians were killed.
The confirmation followed a decision by Iraqi government forces to pause their drive to recapture west Mosul on Saturday because of the high rate of civilian casualties, a security forces spokesman said, a move apparently motivated by the incident on March 17.
With fighting intensifying to recapture Mosul, up to 600,000 civilians remain in Islamic State-held areas in the west of the city, complicating use of air strikes and heavy artilliary to drive the hardline militants from their last major stronghold in Iraq.
Reports on the numbers of civilian dead and wounded have varied but Mosul municipality chief, Abdul Sattar al-Habbo, who is supervising the rescue, said 240 bodies had been pulled from the rubble of collapsed buildings.
Many others were thought to be remain buried in the rubble.
The exact cause of the building collapses was not clear but locals said the strikes could have detonated an IS truck filled with explosives in the heavily-populated area.
US Central Command, which oversees US military Middle East operations, said on Saturday that a review determined that US-led coalition operation, requested by the Iraqi government, had struck Islamic State fighters and equipment "at the location corresponding to allegations of civilian casualties".
It was investigating to determine the facts and the validity of reports of civilian casualties, it said. It did not specify which coalition nation carried out the strike.
A US deputy commanding general for the coalition forces said on Friday that the solution could lie in a change of tactics. The Iraqi military was assessing opening up another front and isolating the Old City, US Army Brigadier General John Richardson said.
Fleeing residents have described grim living conditions inside IS-held parts of Mosul, saying there was no running water or electricity and no food coming in.
Families were streaming out of the northern city, Iraq's second largest - in their thousands each day - headed for cold, crowded camps or to stay with relatives. Hunger and fighting were making life extremely difficult inside the city.
The Iraqi Observatory for Human Rights said that since the campaign on western Mosul began on 19 February, unconfirmed reports said nearly 700 civilians had been killed by government and coalition air strikes or Islamic State actions.
The militants have used car bombs, snipers and mortar fire to counter the offensive. They have also stationed themselves in homes belonging to Mosul residents to fire at Iraqi troops, often drawing air or artillery strikes that have killed civilians.