Dragan Jocic said the clash happened late yesterday when a police patrol tackled a group of armed, masked men in black uniforms who were attacking cars on a road leading to Kosovo.
One of the gunmen was killed in an exchange of fire which lasted around 20 minutes, he said, adding that the gunmen were armed with automatic rifles and rocket-propelled grenades.
Jocic said the gunmen appeared to be robbing passing vehicles, but that ''their attack and defence was professional, conducted with almost military knowledge and experience''.
Serbia's southerly Presevo Valley was the site of an ethnic Albanian rebel insurgency in 2001.
It borders the Albanian-majority province of Kosovo, which has been run by the United Nations and patrolled by NATO since the Atlantic alliance bombed to drive out Serb forces and halt the slaughter of Albanian civilians in a 1998-99 war with separatist guerrillas.
Unease is growing among ethnic Albanians in the region after Russia blocked a Western-backed UN plan to give Kosovo independence from Serbia, forcing new negotiations, due to start in the coming week.
NATO and European Union diplomacy helped end the 2001 insurgency in Presevo Valley, but Albanians in the region are angry at a lack of economic development and investment.
Western diplomats fear any violent flare-up in Kosovo could spread east to the Presevo Valley or south to Macedonia, where the 25 per cent ethnic Albanian minority also fought for greater rights in 2001.
REUTERS RSA RAI2006