Afghan villagers say a foreign airstrike in southern Afghanistan has killed four civilians, three of them children.
The villagers say missiles struck a house in Arghandab district near the southern city of Kandahar before dawn Wednesday, killing three boys and a man from the same family. They protested the attack by bringing the bodies of the four to Kandahar city and chanting anti-American slogans.
U.S. military officials say helicopters operating in the area early Wednesday attacked and killed four militants riding motorcycles in a field away from populated sites. They say the militants were carrying jugs that exploded.
The U.S. military says it is investigating reports of civilian casualties in the incident. Deaths of Afghan civilians in foreign military operations have caused resentment among the public. Afghan President Hamid Karzai has called repeatedly for a stop to air strikes in populated areas.
U.S. General Stanley McChrystal ordered U.S. and NATO troops last month to limit the use of air strikes to try to reduce such casualties. U.S. forces also frequently accuse militants of disguising fighters as civilians.
In other developments, a roadside bomb struck a civilian vehicle in eastern Afghanistan's Nangarhar province Wednesday, killing six people. Officials say the dead include two tribal elders and four workers who were traveling to a meeting with local officials.
Taliban militants have stepped up attacks across Afghanistan ahead of an August 20 presidential election that they have vowed to disrupt.
Some information for this report was provided by AFP, AP and Reuters.