U.S. forces raided a village near the border with Pakistan early Wednesday and killed six people, including two children and a woman, villagers and a government official said.

The raid came a day after NATO said it killed about 12 insurgents in an airstrike in southern Afghanistan, denying accusations from two Afghan lawmakers that civilians were among the dead.

Three men were also killed in Wednesday's raid, including one who used to work as a border policeman patrolling the region in between Afghanistan and Pakistan, said Mirza Gul, a villager from Hom in Khost province, where the violence took place.

One woman and two children were among the six killed, said Khibar Pashtun, a spokesman for the Khost governor.

An official with the U.S.-led coalition said he had no immediate comment but that officials were preparing a statement.

The raid began just after midnight early Wednesday and lasted about an hour, said Gul. Ground troops first arrived with a translator, then more later came by helicopter, said Khadim Khan, a family member.

The governor of Khost province, Arsallah Jamal, has previously called on U.S. forces to seek Afghan assistance before launching nighttime raids, saying Afghans would be in a position to "reduce mistakes."

Going back as far as 2002, President Hamid Karzai has publicly and repeatedly accused the U.S. of heavy-handedness in its counterterrorism operations. The U.S. has said over the years that it has modified tactics to cut down on civilian deaths.

NATO's International Security Assistance Force said the only people killed in Monday's airstrikes in southern Helmand province were militants who had fired on alliance troops.

"The air attack took place in an isolated area where there was no housing or civilian activity," NATO said. "There was no evidence of civilian casualties, which would have been clearly seen by ISAF, and there have been no reports by hospitals in the region of any injuries, or requests for medical aid received."

Dad Mohammad Khan and Mir Wali Khan, the two Afghan lawmakers who said civilians were killed, were in the capital, Kabul, at the time of the strike and relied on reports from local Afghans.

Insurgents and some Afghan civilians hostile to the presence of foreign troops sometimes exaggerate accounts of civilian deaths caused by international forces, or make up claims altogether. Independent verification of battlefield casualties is difficult because the areas are remote and dangerous for travel.

Meanwhile, some of the 3,200 U.S. Marines slated for a seven-month deployment to Afghanistan's volatile south continued arriving at the region's largest base following a call from Canada for more troops.

About 2,300 troops from the 24th Marine Expeditionary Unit, from Camp Lejeune, North Carolina, began arriving in the past days at their new base in Kandahar, the Taliban's former power base.

Canada has 2,500 troops in Kandahar province but has threatened to end its combat role in Afghanistan unless other NATO countries provide an additional 1,000 troops to help the anti-Taliban effort there.

NATO's force is about 43,000-strong, but commanders have asked for more combat troops, particularly for the country's south, where the insurgency is the most active. About 13,000 U.S. troops operate in a separate U.S.-led coalition.

Troops from Canada, Britain, the Netherlands and the United States have done the majority of the fighting against Taliban militants. France, Spain, Germany and Italy are stationed in more peaceful parts of the country.

Last year was Afghanistan's most violent since the 2001 ouster of the Taliban. More than 8,000 people died in violence, the U.N. says.