The Afghan government in Kandahar has accused NATO troops of opening fire on a bus, killing four civilians and wounding about 12 others.
The incident happened after the civilian vehicle approached a military convoy coming in the opposite direction along a highway in the southern province, a statement from the provincial administration said.
“Four civilians were killed,” the statement said, adding that the dead included women and a child. The bus was driving to the western province of Herat, it added.
NATO troops in the convoy evacuated a dozen of the wounded to an alliance-run hospital for treatment, the statement said.
Afghan president Hamid Karzai has “strongly condemned” the shooting.
“Opening fire on a passenger bus is against NATO’s commitment to protecting civilians and is by no means justifiable,” he said in a statement.
The incident came as the Afghan government and NATO attempt a show of unity before a major push against the Taliban in Kandahar, which is considered their spiritual heartland.
Mr Karzai has previously called on foreign forces to minimise civilian casualties and recently travelled to Kandahar with the head of US and NATO troops to shore up support for the planned push among tribal elders.
The president, “with deep grief over this incident”, asked NATO forces to take “serious precautions” to avoid further civilian casualties, the statement from his office added.
NATO’s International Security Assistance Force (ISAF) said it “deeply regrets” killing the civilians.
“ISAF deeply regrets the tragic loss of life in Zhari district (near the city of Kandahar) this morning,” the military alliance said in a statement.
A joint investigation has been launched with Afghan security forces to determine the events that led to “this regrettable loss of life”, it said.