KANDAHAR, Afghanistan (AP) — An Afghan official and local residents say a joint operation carried out by U.S. and Afghan forces last week killed 22 civilians from two families.

The presidential envoy for security in the southern Helmand province, Jabar Qahraman, said Sunday that the raid against the Taliban in the Sangin district killed 13 people from one family and nine from another. Hameed Gul, a local resident, says nine members of his family, including his mother and sister, were killed in Thursday's raid.

U.S. Navy Cpt. Bill Salvin, a military spokesman, says "we are working diligently to determine whether civilians were killed or injured as a result of U.S. airstrikes" carried out to support Afghan forces in and around Sangin. He says the investigation is "continuing and has not reached any conclusions."