KABUL — The United Nations mission in Afghanistan on Tuesday said it was concerned by the increasing number of civilian casualties from air strikes this year, following reports that nine civilians were killed in the eastern province of Kapisa last week.

Air strikes have spiked steeply this year, in a strategy aimed at forcing Taliban militants to accept peace talks, with the number of bombs dropped by the US air force almost doubling in the first six months, to nearly 3,000.

The UNAMA mission said it had received “multiple, credible allegations” that a strike hit the house of a teacher in Kapisa on Saturday, killing nine members of the same family, including three women and four children. Six others were wounded, it said.

“UNAMA reminds all parties to the conflict to uphold their obligations to protect civilians from harm,” it said in a statement.

“The Mission repeats its earlier call for government forces to uphold their commitment to regular review of targeting protocols and ensure mitigation measures and compensation for victims.”

Mohammad Radmanish, a defense ministry spokesman confirmed civilian casualties during a joint operation by Afghan and US forces that involved air support, but gave no details. He said an investigation was underway.

In a statement on Monday, the US military in Kabul said US helicopters supporting an Afghan army operation in Kapisa came under fire from a pro-government militia that had fired in error, and returned fire in self-defense, accidentally wounding six militia members.

“We have no indication of non-combatant casualties,” it said.

The reports underlined one of the problems facing Gen. Scott Miller, the new US commander in Afghanistan who took up his post this month and must balance the need to pressure the Taliban with the need to avoid civilian casualties.

United Nations data shows a jump of 52 percent in the number of civilians killed or wounded in air strikes in the first six months of the year. The UN said 149 civilians were killed and 204 wounded in air attacks in the year›s first half, with women and children comprising more than half the 353 casualties.

Since the figures were reported in July, the UN said it had recorded increasing numbers of civilian casualties from air strikes. — Reuters