People injured in the strike were taken to hospital
At least 20 people have been killed in a missile strike by coalition forces in eastern Afghanistan.
Locals in Nangarhar province say the group was a wedding party and most of the dead were women and children.
But the US has denied this, saying those killed were militants involved in previous mortar attacks on a Nato base.
Meanwhile Afghan President Hamid Karzai has ordered an investigation into a missile attack by US helicopters on Friday in which 15 people died.
The BBC's Martin Patience in Kabul says the issue of civilian casualties is hugely sensitive in Afghanistan.
In the past, Mr Karzai has said that no civilian casualty is acceptable.
The latest claim puts yet more pressure on the Afghan authorities and international forces to avoid civilian casualties, our correspondent adds.
Deh Bala district governor Hamisha Gul told AFP news agency that 22 people had been killed in the strike - 19 of them women and children - and several more wounded.
He said the information had come from police and other officials investigating the incident in the remote area of Nangarhar province.
A man at a hospital in Jalalabad told AP news agency that the group was a wedding party on its way to the groom's house.
"They stopped in a narrow location for rest. The plane came and bombed the area," he said.
"There were between 80 to 90 people altogether. We have carried six of the injured to this hospital, and more might be coming. The exact number of casualties is not clear."
However, US military personnel have denied reports that the group were civilians.
Coalition media officer Capt Christian Patterson told AFP they had received no reports of civilian casualties.
"It was not a wedding party, there were no women or children present," he said.
In a separate incident on Friday, 15 civilians were reported to have died in a missile attack in Kunar province.
Mr Karzai has ordered an investigation into the incident, which the US said killed only militants.
A statement released by the presidency on Sunday said Mr Karzai "has repeatedly emphasised the [need for] co-ordination of military operations and has been deeply saddened since learning about this incident".
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