The governor of the central Afghan province of Uruzgan says he wants the US military to hand over the "informer" who told it to bomb villages in his province this week, killing 46 civilians.
"If they [Americans] don't submit the informer to us, then they are our enemy," Mr Jaan Mohammad told said.
"The Americans for sure know who this person is. We know him too, but we don't want to reveal his name."
The US military has said it had received reliable information from several sources that senior Taliban leaders were sheltering in a remote Uruzgan village close to Deh Rawud, near the birthplace of fugitive Taliban leader Mullah Mohammad Omar.
A special forces team went in to "cordon and search" the village, but called in air strikes after seeing anti-aircraft fire coming from the area directed at coalition warplanes.
The Afghan government says 46 people were killed, including women and children attending a wedding party, when US planes attacked several villages on Sunday night and Monday morning.
But a US investigating team, which has been in the area since Wednesday, said it has so far only seen five graves.
Analysts said mounting anger about the civilian casualties could undermine the Western-backed government of President Hamid Karzai, and complicate US efforts to track down Taliban remnants and followers of Osama bin Laden.
Mr Karzai yesterday called for greater consultation from the US on its military operations in Afghanistan.
"Arrangements should be clear," he said. "Any operation needs to be coordinated with the Afghan defence ministry ... Our people should be immune. People should not be hurt and the campaign against the Taliban and terrorism must not become the cause of people's harassment."
He said he would soon travel to Uruzgan to visit mourning families there and urged the United States not to carry out military operations based only on the intelligence of informers.