Coalition airstrikes have targeted a gathering of Islamic State leaders at a house in northern Iraq, a US defence official has said.
Senior IS officers were meeting in al Qaim, a town near Mosul which is under the Islamist group's control. After the strikes began, militants evacuated a nearby hospital and used loudspeakers to ask for blood donors.
The bodies of 50 militants have since been transported to a morgue in Mosul, according to Reuters.
Unconfirmed reports from the news agency suggest that the leader of IS, along with his deputy, were killed in the attack.
It is unclear whether top commander Abu Bakr al Baghdadi was among the militants targeted, a US official said.
Hailed as the world's most wanted man, al Baghdadi has declared himself the caliph, or supreme leader, of the vast areas of territory in Iraq and Syria under IS control.
Washington has offered a $10m (£6m) reward for his capture.
US national security analyst Arash Aramesh told Sky News: "If he is in fact dead, yes it will deal a major blow to the organisation but let's not forget there are other commanders both in the military and political wings that can replace al Baghdadi.
"This organisation with one dead leader is not going to be finished. This is going to be a continued, long-term campaign not just to rid the region of IS but from the ideology that creates organisations like IS, al Qaeda, Boko Haram and the Taliban."
The airstrikes also destroyed a convoy of 10 armed IS trucks, US Central Command said.
In a statement, its spokesperson added: "This strike demonstrates the pressure we continue to place on the IS terrorist network and the group's increasingly limited freedom to manoeuvre, communicate and command."
Meanwhile, a series of explosions have killed dozens of people across Iraq.
Four bombings killed least 43 people in and around Baghdad on Saturday. The deadliest blast hit the city's Shi'ite district of Sadr City, where a car bomb tore through a commercial area killing 11 people.
On Friday, a suicide truck bomber struck the convoy of a top Iraqi police officer killing eight people, including the ranking official. Iraqi authorities said the attack bore the hallmarks of IS.
US President Barack Obama has authorised the deployment of up to 1,500 more US troops to bolster Iraqi forces, including into Anbar province, where battles with IS militants have been fierce.
A statement from Iraqi Prime Minister Haidar al Abadi's office said: "This step is a little late, but we welcome it."
