The United Nations' mission to Afghanistan said on Thursday they had asked the Taliban to hold a 'credible investigation' into reports of extrajudicial killings, including of children, in northern Daikundi province.
The Taliban have said that a gunfight in Daikundi between security force members and suspected armed rebels had resulted in deaths but denied that children had been killed.
The UN mission (UNAMA) said it was working to establish what had happened.
"(There are) very serious reports of civilian casualties, with extrajudicial killings, at least eight fatalities, including children," the mission said in a tweet. "UNAMA has engaged Taliban on the need for credible investigation and accountability."
A Taliban ministry of information spokesperson did not immediately respond a Reuters request for comment on the UN statement.
Interior ministry spokesperson Abdul Nafi Takor said earlier this week that armed rebels had been identified in the area and security forces had asked local elders to intervene. He added that after the men did not follow the elders' request to lay down their weapon, security forces entered a property where the suspected rebels were present and there was firing from both sides.
"Nine armed people were killed and four people were injured in the mutual firing. The dead people were all armed and trying to rebel, it is not true that children were killed, or any other harm was done there," he said.
The Taliban say they are focused on securing the country since taking over last year as foreign forces withdrew. Some resistance groups have said they have been carrying out operations, mostly in the northern province of Panjshir where they have clashed with Taliban fighters.
In September, the Taliban said they had killed 40 resistance members, including four commanders, in Panjshir.