At least 50 soldiers and civilians were reported to have been killed in a battle between ethnic Tajiks and Pashtuns in western Afghanistan last night.
The Pakistan-based Afghan Islamic Press (AIP) said the Tajik-dominated forces of Governor Ismail Khan and forces loyal to local warlord Mohammad Kareem Khan fought a pitched battle near Ghurian, west of Herat city.
The AIP quoted a spokesman for the Pashtun warlord as saying the Tajik forces, backed by tanks, had attacked Pashtun positions. He accused Ismail Khan's forces of torching the houses of Pashtuns and said many people were burned alive.
A spokesman for Ismail Khan, who is the governor of Herat province, told Reuters it was a police action by government forces against "drug smugglers". He said he had reports that several of the alleged smugglers had been killed and Kareem Khan and his supporters had fled.
The spokesman for Kareem Khan demanded that President Hamid Karzai and the United Nations send a delegation to the area to observe the situation.
The ethnic clashes underline Afghanistan's continued vulnerability to infighting since a new government led by Mr Karzai took power to succeed the Taliban.
Anger over the division of power after the fall of the Taliban - mainly by Pashtuns from the south - is widespread. Mr Karzai is himself a Pashtun but his government is dominated by minority Tajiks from the north.