Afghan villagers in the eastern province of Kunar say 35 civilians have been killed in separate air attacks by international forces.
The villagers said neighbours in Watapour were burying 10 people killed in a strike when planes attacked again, killing 25 more people.
The Nato-led force said it had launched air strikes in the area, but had not had reports of civilian casualties.
Meanwhile, US forces killed 33 Taleban in the southern province of Uruzgan.
Afghan defence officials said the militants had been killed after they attacked a police checkpoint in the Charchino district on Thursday night.
The BBC's Charles Haviland in Bamiyan says there are widely diverging accounts of the two air strikes in Kunar by the Nato-led International Security Assistance Force (Isaf).
Villagers from Watapour said 10 people, including nine members of a single family, were killed in one such bombardment late on Thursday.
One of the villagers, Shafiqullah Khater, told the BBC he had witnessed other civilians being killed during the funeral for the earlier victims on Friday.
"When we were burying the 10 people, the aeroplanes started a bombardment and another 25 people were killed," he said.
"Among the 25 were some elders from the local community and religious leaders."
Afghan defence officials said there may have been some civilian casualties, but fewer than the locals said.
A spokesman for Isaf rejected the claims and said its forces had been attacked from multiple positions and responded by calling in air strikes against militant positions, including a compound.
"Initial indications are that there were a number of insurgent casualties," Maj John Thomas said.
"At this time there is no reason for us to believe that there are any civilian casualties of any type."
Our correspondent says the scene of the military action is remote and casualty figures are hard to verify.
However, in the last few weeks the number of civilian casualties caused by international air strikes and shootings has given rise to major controversy here, he adds.