US military officials in Afghanistan now say eight Afghan civilians were killed after a suicide attack and ambush by gunmen on a US convoy.
Earlier, US officials said 16 civilians died in the incident near the eastern city of Jalalabad, but the figure was later revised without explanation.
The military says US troops opened fire after a suicide bomber rammed their convoy with his vehicle and other militants began shooting. US officials say it is not clear if the civilians were killed by the American troops or the attackers.
Afghan police said it appeared at least some civilians were killed by US gunfire. The Associated Press news service is quoting wounded Afghans as saying US forces fired indiscriminately along a six-mile stretch of the busy highway where the incident took place.
Meanwhile, British defense officials have identified two NATO soldiers killed Saturday as members of a British artillery unit.
They said the two men were killed in a rocket attack during operations in the Sangin area of Helmand province in southern Afghanistan.
Helmand has seen the most fighting this year, with regular clashes with Taleban forces.