Afghan officials have said a NATO airstrike targeting insurgents in the east of the country has killed at least eight civilians, including seven women and children.

NATO said the strike claimed the lives of ten militants travelling in a pick-up truck.

Civilian deaths have been a long-running source of friction between Afghan President Hamid Karzai and his international backers.

Mr Karzai has forbidden Afghan troops from calling for foreign air strikes, but that ban is not always adhered to.

NATO advises crews not to fire at or bomb populated areas.

"We can confirm that we undertook a precision strike in Watarpur district of Kunar, and are able to confirm ten enemy forces killed," said a spokeswoman for the NATO-led International Security Assistance Force.

Watarpur is a rural district in the north of Kunar, a mountainous province that shares a long and porous border with lawless tribal areas of Pakistan.

The province has long been considered a transit hub for foreign insurgents, including al-Qaeda members, who fight alongside the Taliban.

While Kunar police chief Abdul Habib Sayed Khil and provincial governor Shuja ul Mulk Jalala said civilians had been killed in the incident, the NATO spokeswoman said it had received no reports of civilian casualties.

Mr Jalala and Mr Khil said at least eight civilians, including three women, four children and the truck's driver, had been caught up in an airstrike targeting Taliban fighters.

They said the truck was hit after the driver gave the Taliban fighters a lift.