Civilians are feared dead in an attack that damaged a mosque and nearby homes in a part of the Iraqi city of Mosul controlled by so-called Islamic State (IS).
Witnesses told the BBC that the Omar al-Aswad mosque in the Farouq district of the old city was hit from the air.
Drones belonging to the Iraqi police and US-led coalition bombers were flying overhead at the time, they said.
A coalition spokesman told Reuters he was unaware of a strike on the mosque.
The news agency also cited Iraqi military media officers as saying the battle for the city was continuing and that troops were targeting IS positions wherever they could. However, it added, they did not say whether the mosque was among those targeted.
Three residents told Reuters the mosque was run by IS, and that both militants and civilians were killed. They could not give precise casualty figures because their movements were restricted.
The mosque is in the old city, close to the Great Mosque of al-Nuri, where IS leader Abu Bakr al-Baghdadi proclaimed the creation of a caliphate in July 2014 after his group seized control of large swathes of northern and western Iraq.
The reported attack comes as fighting intensifies between IS militants and Iraqi forces advancing into south-western Mosul after recapturing the east of the city.
IS militants are resisting the onslaught with suicide car bombs, sniper and mortar fire, and reportedly launched a counter-attack during an overnight storm.
The Iraqi government says at least 26,000 civilians have fled in the past 11 days.
There is also deep concern for the up to 700,000 who remain there. Food supplies are running very low, and some families say they cannot find any food at all.