The incident took place Wednesday in Khost province's Domandera district, according to Khost upper house member and foreign relations chief Arifullah Pashton.

There was no immediate reaction from NATO's International Security Assistance Force about civilian casualties in Khost. But ISAF said it was investigating allegations of civilian casualties in an airstrike targeting an insurgent in Ghazni province, in the southeast.

Pashton said hundreds of people in the district demonstrated against the alliance on Thursday and chanted, "Death to the United States" and "Death to NATO."

Civilian casualties in the war between coalition forces and militants have generated grass-roots anger toward the combatants, and ISAF has been working for years to tackle the problem.