Afghan President Hamid Karzai issued a statement Monday condemning the incident and ordering an investigation. Officials say the attack took place Sunday in the Kunar province.
NATO officials say they had no further information but are investigating the reports.
Civilian deaths from coalition airstrikes are a contentious issue in Afghanistan. U.S. commanders have made protecting civilians a top priority in the new U.S.-led war strategy aimed at countering the Taliban.
Separately, a joint force of Afghan and international troops are searching for three Afghan police officers missing since Taliban militants stormed a security outpost in the northwestern Badghis province on Sunday. Two police officers were killed in that attack.
Also Monday, Spain's defense minister met with Spanish troops guarding Kabul's airport. Spanish media say Carme Chacon pledged that Spanish forces will train some 2,000 Afghan troops in the coming year.
Spain currently has about 1,000 troops serving in NATO's Afghanistan mission. The Spanish parliament is expected to approve plans to deploy several hundred more soldiers in the coming months.
Some information for this report provided by AP, AFP and Reuters.