The allegations come amid a new surge of criticism over civilian deaths during attacks by foreign forces, a debate that underlines how the five-year-old war against insurgents is also a struggle for hearts and minds among long-suffering Afghans and voters in NATO countries.
President Hamid Karzai and others have long complained that civilian losses in NATO or U.S.-led operations are undermining the effort to stabilize Afghanistan and prevent a Taliban comeback. The deaths are "difficult for us to accept or understand,'' Karzai said Thursday.
NATO commanders are adamant that the militants -- not foreign forces -- deserve most of the blame for the toll among civilians.
An alliance statement said NATO aircraft struck after Taliban fighters attacked troops from NATO's International Security Assistance Force about 15 kilometres northeast of the town of Gereshk.
"A compound was assessed to have been occupied by up to 30 insurgent fighters, most of whom were killed in the engagement,'' the statement said.
Lt.-Col. Mike Smith, a NATO spokesperson, expressed concern about Afghan police reports that civilians also died in the air strike. But he said insurgents chose the time and place for their attack, so "the risk to civilians was probably deliberate.''
"It is this irresponsible action that may have led to casualties,'' he said.
The air strike killed 20 militants, but it also wiped out two civilian families totalling 25 people, including nine women, three babies and a mullah, provincial police Chief Mohammad Hussein Andiwal told Associated Press.
"NATO was targeting the areas where the (insurgent) fire was coming from . . . and two compounds were completely destroyed, and the families living in those compounds were killed,'' he said.
Military commanders said their forces have to be free to respond to attacks.
"If someone is firing at our troops they have the right to defend themselves and have the right to fire at a position which is firing at them,'' said another NATO spokesperson, Maj. John Thomas. "If the enemy has put themselves in an area where they are firing from among civilians, this is when we sometimes have casualties.''
Thomas said NATO forces try to monitor a target from the air and ground for any civilians. "But in the cases like (Gereshk), when we respond to an ambush or an enemy attack, things move a little bit more quickly,'' he said.