The incident took place at the town of Zegra, south of Gnjilane, where the American contingent of Nato forces have their headquarters.
According to US military sources, a group of civilians in a car approached the checkpoint and opened fire with Kalashnikovs. The marines returned fire and in the ensuing gun battle one of the attackers was killed. There were no US casualties.
US forces brought in reinforcements by helicopter and there were reports of a second engagement in which two gunmen were said to have been wounded.
The killing is the first by Nato forces since British paratroopers shot dead a member of the Serbian Special Police Force (MUP) last weekend.
It was unclear whether the gunmen involved in the shoot-out with marines were Serbs or Kosovo Albanians.Reuse content