Hundreds of Yugoslav soldiers and police officers swept into a buffer zone next to the Kosovo boundary yesterday in a NATO-backed effort to clamp down on ethnic Albanian guerrillas. But while the operation in remote and mountainous southern Serbia was apparently carried out peacefully, violence flared up inside Kosovo and in neighbouring Macedonia.
The soldiers, armed with automatic rifles and checking for landmines as they moved along roads into a pocket of Serbian land on the southern tip of the 5 km buffer zone where it also touches the Macedonian border.
The deployment is part of a drive to cut any links between ethnic Albanian armed rebels who have been operating in Serbia's Presevo Valley for more than a year and a similar group which has emerged in Macedonia in the past few weeks.
The guerrilla violence has prompted international fears that serious conflicts could erupt again in the Balkans, upsetting hopes for an era of peace following the departure of the former Yugoslav president, Mr Slobodan Milosevic.
EU monitors and officers from Kosovo's NATO-led Kfor peacekeeping force were on hand to observe the deployment, which began in the early morning. "So far, as far as I'm able to tell, the army has behaved perfectly well," a British officer, Lt-Col Richard Barrons, said in the village of Miratovac.
The guerrillas say they are protecting local ethnic Albanians from Serbian state persecution and that the region should have the right to join ethnic Albanian-dominated Kosovo.
NATO worked closely with Yugoslav officers - their enemies in the Kosovo conflict only two years ago - in planning the deployment in an effort to reassure local ethnic Albanian civilians there would be no repeat of Milosevic-era repression. But in Mitrovica, Serbs threw rocks and bottles at peacekeepers, attacked three UN police officers in their homes, set ablaze at least one car and one house, the United Nations Mission in Kosovo (UNMIK) said. A grenade was also thrown at one house.
The angry crowds, protesting against the arrest of several Serbs suspected of assaulting police officers, entered the homes of non-Serbs and UN police.
Ethnically-divided Mitrovica has been a flashpoint since NATO and the UN took control of Kosovo in mid-1999 after NATO's bombing campaign. But Macedonia is a new trouble-spot, although analysts have long pointed to the former Yugoslav republic's fragile population mix of two-thirds ethnic Macedonians to one-third Albanians. Heavy machine gun and mortar fire could be heard near the western, mainly ethnic Albanian town of Tetovo and authorities said security forces had been attacked by gunmen there.
"Unfortunately we have information that new flashpoints might appear throughout the country," a spokesman for Macedonia's Interior Ministry, Mr Stevo Pendarovski, said in the capital, Skopje.