KABUL, Afghanistan  There is a “fair chance” that a NATO jet inadvertently killed five Afghan civilians during a shootout with Taliban fighters in a village in southern Afghanistan earlier this week, an American official said Saturday.

Some details were still unclear, but a local Afghan official and two witnesses said that the civilians were killed Thursday afternoon when a NATO aircraft fired on a house after a firefight with Taliban militants who had attacked a NATO convoy. The Taliban were operating in Luchak, a farming village in central Helmand Province, the epicenter of the insurgency. When the convoy arrived in Luchak, about a half-dozen Taliban fighters opened fire from behind a wall next to a house.

After a 10-minute exchange of fire, the insurgents ran away, the witnesses said. Then, about 10 minutes later, a pair of helicopters appeared in the sky, the villagers said.

Maj. Michael Johnson, a NATO spokesman, said the aircraft was a plane that had come in support of the troops on the ground.