Four children were among 11 people killed when a US air strike targeted an Afghan village in southern Oruzgan province, local officials say.
The US is hunting for Taleban troops in the south and east
The raid struck the village of Saghatho in Charcheno district early on Sunday morning, governor Jan Mohammad Khan told the BBC.
The US military in Kabul said it had no information about the raid.
The deaths came a day after US forces had entered the village in search of Taleban fighters.
The governor said the 11 victims, three of them women, were buried at about 9am on Sunday.
District chief Abdul Rahman told AFP and AP he did not know why the US had bombed the village, which is 330 kilometres (200 miles) south of the capital, Kabul.
"They were simple villagers, they were not Taleban."
He said some villagers were scared of being arrested by the Americans and had left the village with their
"As soon as they arrived near a river, planes bombed them and killed [them]."
Governor Khan had a different version of events.
He said the US forces had spotted ammunition in one home during their search of the village and it was this home that was struck at about 4am on Sunday.
A spokesman for the US military in Kabul, Lieutenant-Colonel Bryan Hilferty, said he did not know about the raid or civilian deaths.
But Colonel Hilferty said that US forces had killed five "armed anti-coalition militia members" in a weekend air assault in Oruzgan's Deh Rawood district.
In 2002, a botched US strike killed 48 wedding party members
He also said three US soldiers had been injured by shrapnel when about 15 attackers struck a US base in Deh Rawood early on Sunday.
The BBC's Andrew North in Kabul says Oruzgan, north of the city of Kandahar, is known to be a stronghold of Taleban support.
Around 11,000 US-led forces are searching for Taleban and al-Qaeda suspects in southern and eastern Afghanistan.
Afghans say that several thousand civilians have been killed in US-led attacks since the campaign against Taleban forces began.
In early December, six Afghan children died during a US assault in eastern Paktia province.
The next day, nine more died in a field in Ghazni province after a US air attack.
In July 2002, 48 members of a wedding party in Deh Rawood died when they were hit by US bombers.