KABUL, Afghanistan — The governor of Helmand province in southern Afghanistan on Sunday accused U.S.-led forces of killing at least 14 civilians in a bombing raid called in by besieged U.S. Marines.

Among the dead in the Saturday incident, according to a statement from the governor's office, were five girls, seven boys and two women.

The 14 were inside two houses that were struck by bombs or missiles after U.S. Marines came under attack at 8 a.m. in the Nawzad district of Helmand, the statement said.

A spokesman for the U.S.-led coalition confirmed the attack, and said it was under investigation.

"An assessment team has been sent to the area to investigate and we are waiting for the team to complete their findings before releasing any further information," Maj. Tim James said.

Helmand is a volatile province that shares a border with Pakistan's Baluchistan province, where Afghan and U.S. officials believe senior Taliban officials are based. Much of the U.S. surge of troops into Afghanistan in the past year has been focused on breaking the Taliban's grip there and in Kandahar, the province directly east that is the birthplace of the Taliban movement.

Civilian casualties have been a source of tension for years between the U.S.-led International Security Assistance Force, as the U.S.-led coalition is called, and the government of Afghan President Hamid Karzai. Both the current U.S. commander, Army Gen. David Petraeus, and his predecessor, Army Gen. Stanley McChrystal, issued orders limiting when air strikes can be called in in hopes of preventing civilian casualties, but Karzai continues to complain that coalition military actions result in the deaths of too many innocents.

Only Saturday, Karzai issued a statement saying he'd asked his defense minister to halt so-called night raids of the homes of suspected Taliban supporters by ISAF forces because they too often result in civilian deaths.

Violence has risen dramatically in the past month as Taliban insurgents step up their attacks against Afghan and NATO troops across the country.

(Shukoor is a McClatchy special correspondent.)

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