NATO's US-led International Security Assistance Force said it had targeted insurgents, but had been made aware of "possible ISAF-caused civilian casualties" numbering five to eight, and extended its sincerest condolences over the "tragic loss of life".

Civilian casualties from NATO air strikes have strained relations between the United States and Afghan President Hamid Karzai. In June, ISAF ordered an end to air strikes on homes, except as a last resort.

Sunday's attack came shortly before dawn, an Afghan official said, in the area of Dilaram village, in Alingar district of Laghman province. The women were said to have set off to the mountains to collect fire wood.

Sarhadi Zwak, a provincial spokesman, said it was a unilateral military operation not coordinated with Afghan forces.

"In this raid, eight women are killed and another eight women are wounded. The (provincial) governor has appointed a delegation to investigate," Zwak told AFP.

Dozens of tribesmen from Alingar drove into the provincial capital, Mihtarlam, carrying the bodies of some of the victims they said were killed.

ISAF said its troops had called in an air strike against about 45 insurgents "after positively identifying hostile intent" and that "a large number of the insurgents" were killed.

In June, ISAF commander US General John Allen flew to Logar province, south of Kabul, to apologise over the deaths of civilians, including women and children, in an air raid.

NATO said the strike targeted insurgents in a home but Afghan officials say 18 civilians died in the attack. Karzai expressed outrage and cut short a visit to Beijing.

It was the second time within a month that Allen had to admit civilian deaths in air strikes, which are part of NATO's arsenal against a 10-year Taliban insurgency.

According to the United Nations, Afghan civilian casualties were down 15 percent in the first half of 2012, the first such decline in five years.

It said pro-government forces, which include NATO, were responsible for 10 percent of civilian casualties in 2012 and insurgents for 80 percent. The remaining 10 percent was attributed to unknown groups.