KABUL: At least 13 civilians were killed in an airstrike that hit a residential building in a volatile district of eastern Nangarhar province early Wednesday, an Afghan official said.
The U.S. military in Afghanistan said the incident was being investigated.
Esmatullah Shinwari, a Nangarhar lawmaker, told The Associated Press that a crowd had gathered at the house in Achin district, near the Pakistan border, to welcome home a tribal leader returning from the Hajj, an annual Muslim pilgrimage to Saudi Arabia.
At least 12 people were wounded in the strike, including the tribal leader, he said.
Hazrat Hussain Mashreqiwal, the spokesman for the provincial police chief, said that the airstrike had targeted Islamic State group loyalists. Afghan forces backed by the U.S. military have been battling IS fighters in Achin for months.
The spokesman for the U.S. military in Afghanistan, Brig. Gen. Charles Cleveland, confirmed a "counter-terrorism air strike in Achin district" early Wednesday.
"U.S. forces did conduct one counter-terrorism air strike in Achin district, Nangarhar province, Sept. 28, and for operational security reasons we do not discuss the details of counter-terror operations," Cleveland said in a statement.
"We are aware of some claims of Afghan casualties," he said, adding that investigations were underway.