Updated

Afghan President Hamid Karzai on Thursday demanded an explanation from the new top commander of U.S. and NATO troops for an airstrike that local officials say killed 10 civilians, half of them children.

The death of Afghan civilians during military operations has been one of the most contentious issues of the 11-year-old war.

Afghan officials said two houses were bombed late Tuesday during a joint Afghan-NATO operation in the Shigal district of the northeastern Kunar province, which borders Pakistan. Provincial police chief Ewaz Mohammad Naziri said five boys, four women and one man were killed along with four senior Taliban leaders, who were gathered in one of the homes.

The U.S.-led coalition has launched a probe to determine what happened.

Gen. Joseph Dunford, who took over Sunday for Gen. John Allen as the commander of all allied forces in Afghanistan, expressed "his personal condolences for any civilians who may have died or been injured as a result of the operation," according to a coalition statement.

Jamie Graybeal, a spokesman for the U.S.-led coalition, said Dunford told Karzai that the coalition was conducting an assessment of circumstances surrounding this incident and that coalition officials would meet with local village elders and families of anyone harmed in the operation "to personally to express our condolence."

Karzai's office said Dunford explained that the coalition and Afghan forces were targeting members of al-Qaida when they summoned air support to the province.

"Pointing to a commitment Gen. Allen had previously made not to conduct any airstrike or bombing in residential areas, President Karzai reminded that such incidents must strictly be avoided in future and any recurrence is not acceptable," the statement from Karzai's office said.

The reported attack came as President Barack Obama announced Tuesday in his State of the Union speech that he will withdraw about half of the 66,000 U.S. troops in Afghanistan within a year — a step toward withdrawing all foreign combat forces by the end of 2014.