Sixteen Afghan civilians were killed after a "complex" Taliban ambush on a US convoy involving a suicide car-bomb attack and militant gunfire, the US military in Afghanistan said today.
Afghan authorities said 10 civilians were killed and more than 30 wounded, at least eight of them when US troops opened fire after the blast. They said they were not aware of the convoy coming under fire from gunmen after the blast.
Hundreds of angry Afghans protested after the violence, blocking the road near the eastern city of Jalalabad where the attack happened and throwing stones at police.
The US military said its troops had returned fire in defence after a "complex ambush" but it did not make clear how the 16 civilians were killed and 24 wounded. The incident was being investigated by US and Afghan forces, it said.
Earlier, a provincial government spokesman said civilians died when troops in the convoy opened fire after the blast.
"The soldiers in the convoy fired in self defence resulting in the killing and wounding of some civilians," said the spokesman, Noor Agha Zwak.
Provincial police spokesman Abdul Ghafour said the US troops were responsible for the civilian casualties. Deputy provincial governor Abdullah Wafa said the deaths of 10 civilians had been registered.
The US military laid the blame on the Taliban.
"We regret the death of innocent Afghan citizens as a result of the Taliban extremists' cowardly act," US spokesman Lieutenant-Colonel David Accetta said in a statement.
One member of the US force was wounded.
The killing of civilians is sensitive for foreign troops and the Western-backed government of President Hamid Karzai.
Bombing and accidental shootings by Western forces feeds resentment of the government and its allies and even bolsters support for the Taliban, analysts say.
More than 45,000 foreign troops are in Afghanistan battling a resurgent Taliban who have threatened a spring offensive after the bloodiest year since their ouster by US forces in 2001.
In a separate incident, two NATO soldiers were killed during combat operations in the south on Saturday. Their nationalities were not given.