Ethnic Albanian guerrillas and Serbian security forces clashed today close to the boundary with Kosovo and one policeman was reported killed with six other people wounded.
Senior officials including Deputy Prime Minister Nebojsa Covic who went to the scene of the latest fighting in the village of Lucane found themselves trapped by enemy fire.
"They've been shooting at the house we're in for several hours," said Biserka Matic, a member of a government coordination body set up to seek a peaceful resolution to the crisis in southern Serbia.
"The entire coordinating body is here, as well as a number of television crews and reporters, she told B92 radio. All the cars parked outside the house are riddled with bullets.
"We don't dare poke our noses outside as they are firing at everything that moves," she added.
The officials later made it to safety in nearby Bujanovac, where Ms Matic said the fighting had lasted eight hours.
Frequent clashes between guerrillas and police has claimed more than 30 lives over the last year in southern Serbia and alarmed Western capitals hoping for an era of Balkan peace after the downfall of Serb autocrat Slobodan Milosevic last October.
Violence has spread in recent weeks into nearby Macedonia, where authorities have also placed the blame squarely on ethnic Albanian militants.