The bombing occurred around midnight, the United Nations statement said. “Foreign and Afghan military personnel entered the village of Nawabad in the Azizabad area of Shindand district,” it said. “Military operations lasted several hours during which airstrikes were called in.

Image Residents of Azizabad, Afghanistan, on Saturday walked around a home that was destroyed in an American airstrike on Friday. Credit... Reza Shirmohammadi/Agence France-Presse — Getty Images

“The destruction from aerial bombardment was clearly evident,” the statement said, with seven or eight houses “having been totally destroyed and serious damage to many others.”

Mr. Safi, the member of Parliament, said the villagers had been preparing for a ceremony the next morning in memory of a man who died some time before. Extended families from two tribes were visiting the village, and there were lights of fires as the adults cooked food for the ceremony, he said.

How the military came to call in airstrikes on a civilian gathering is unclear. Two members of Parliament, Mr. Safi and Maulavi Gul Ahmad, who is from the area, said the villagers blamed tribal enemies for giving the military false intelligence on foreign fighters gathering in the village.

Mr. Ahmad blamed United States Special Forces, who are training the Afghan Army and were present in the joint operation. “I can’t blame the Afghan National Army for the incident, as they had no authority for leading the operation,” he said.

The government commission met with the commander of United States forces in Herat Province, but he declined to answer their questions, saying the United States military was conducting its own investigation, Afghan government officials said.

The Defense Department said it would not have a separate statement on the bombing beyond the one issued by the American military headquarters in Afghanistan. That statement said in part that the operation killed 25 militants, including a Taliban commander, Mullah Sadiq, and 5 “noncombatants.”