US looking into Afghanistan airstrike which may have killed civilians

The U.S. military confirmed it was looking into accusations that an airstrike targeting Islamic State loyalists hit a residential building in eastern Afghanistan early Wednesday, killing 13 civilians.

Esmatullah Shinwari, a lawmaker from the volatile eastern Nangarhar province, told The Associated Press a crowd had gathered at the house in Achin district, near the Pakistani border, to welcome home a tribal leader returning from the annual hajj pilgrimage to Saudi Arabia. At least 12 people were wounded in the strike, including the tribal leader, he said.

Most airstrikes in Afghanistanare carried out by the United States, and while Afghanistan has its own warplanes, another Afghan official said they had not carried out any strikes in the area. The U.S. military said it had carried out a "counterterrorism airstrike" in the area.

"U.S. Forces - Afghanistan takes all allegations of civilian casualties very seriously," U.S. Army Col. Michael T. Lawhorn told Fox News.

Afghan forces backed by the U.S. military have been battling ISIS fighters in Achin for months.

The spokesman for the U.S. military in Afghanistan, Brig. Gen. Charles Cleveland, confirmed a "counterterrorism airstrike in Achin district" early Wednesday. He said that for "operational security reasons" he could not provide further details.

Noor Ahmad Habibi, deputy spokesman for the Nangarhar governor, said the Afghan air force had not carried out any operations in Achin district on Wednesday.

"According to our information, the airstrike in Achin district this morning was carried out by foreign forces," he said.

Fox News' Lucas Tomlinson and The Associated Press contributed to this report.