The Nato force in Afghanistan has launched an investigation into an attack by a drone aircraft on an Al Qaeda member, which killed eight women and children according to a senior Afghan official.

Civilian casualties have been a long-running source of friction between Afghan President Hamid Karzai and his international backers. Karzai has forbidden Afghan troops from calling for foreign air strikes, though the ban is not always adhered to.

The attack took place on September 7 in the eastern province of Kunar. Nato’s International Security Assistance Force (ISAF) initially said “ten enemy forces” had been killed, and added that it had no reports of any civilian casualties.

“When allegations arose of civilian fatalities as a result of this mission, ISAF initiated an investigation,” said a force spokeswoman, Colonel Jane Crichton. “The air strike targeted insurgents riding in a truck.

“There were no signs of civilians in the vicinity,” she added.

Karzai, however, had strongly condemned the attack from the outset. He called it an attack on women and children which was “against all internationally agreed principles”.

Afghan security officials in Kunar said Nato special operations forces had launched the drone to attack an Al Qaeda operative.

“Four women, four children, two drivers, a merchant and three suspected (insurgents) were killed,” said Kunar governor, Shuja ul-Mulkh Jalala.

A four-year-old girl was also seriously wounded, Jalala added.

Civilian casualties have been on the rise in the Afghan war, adding to concern about security as Western forces prepare to leave by the end of next year.

Karzai has been supported by the United States (US) and its allies since he was installed as leader shortly after the Taliban were ousted in 2001, but his relationship with them can be fraught.

Karzai has appealed to the Taliban to give up their war and has expressed the hope that violence will end once Western forces leave. The Taliban call him a US “puppet”.