About 50 Afghan civilians have been wounded in an air strike by US-led forces on a group of Taleban leaders holding a meeting in Helmand province.
The injured said they were at a market when the aircraft struck
Witnesses have told the BBC that a large number of civilians were killed.
The attack on Thursday night reportedly targeted Dadullah Mansour, the group's military commander in the south, and Abdul Rahim, its commander in Helmand.
The Afghan defence ministry said its intelligence reports indicated three militants, including Rahim, had died.
Officials are trying to confirm if Dadullah Mansour, the brother of the late Taleban military commander, Mullah Dadullah, was among those killed.
The Taleban leaders had gathered to watch the public execution of two people on charges of co-operating with the government, ministry spokesman Gen Zahir Azimi said.
The US-led military coalition could not confirm Gen Azimi's account, but confirmed it had conducted an airstrike against "two notorious Taleban commanders" in a remote area of Baghran district in northern Helmand.
"During a sizable meeting of senior Taliban commanders, coalition forces employed precision-guided munitions on their location after ensuring there were no innocent Afghans in the surrounding area," the coalition statement said.
The coalition gave no word of casualties, but a BBC reporter in the provincial capital, Lashkar Gah, says about 50 people were admitted to hospital there with injuries.
The injured said they had been at a market when the bombardment happened and that there had been a large number of civilian deaths.
Helmand's police chief, Mohammad Hussein Andiwal, confirmed that wounded civilians had been admitted to hospital.
"I can confirm there were heavy bombardments," he told the Reuters news agency.
"We have heard of heavy casualties too and have sent a team to investigate this."
The news of civilian casualties comes only days after the secretary-general of Nato said it was considering the use of smaller bombs in Afghanistan to try to curb the rising number of civilians killed during operations against the Taleban.
Afghanistan's President, Hamid Karzai, recently warned Western troops against treating Afghan lives cheaply.