The West's strategy in the Balkans was facing a double crisis last night with Bosnia's Serbs ready to break from the rest of the country and Kosovo's guerrillas split over whether to accept a US-drafted peace plan.
Western troops and aid workers were ordered to leave the key Bosnian Serb town of Bijelinja last night by officials of the ruling hardline nationalist Radical Party and NATO troops across the country were on alert following a series of grenade attacks.
The most serious crisis was in Bosnia, with the parliament which controls Serb-held territory poised to repudiate the key conditions of the 1995 Dayton peace agreement.
In a day-long emergency debate, Serb representatives rejected decisions by Western agencies this weekend to sack their president, Mr Nikola Poplasen, and to place their strategically vital town of Brcko under international supervision.
The parliament was due to vote, in effect, to cut links with Croat and Muslim parts of Bosnia, breaking the central tenet of the 1995 Dayton peace agreement that all Bosnians must live in a single state.
Serb officials will be withdrawn from all common institutions and they will refuse to implement a decision by a US arbitrator to give control of the key town of Brcko, on Bosnia's northern border with Croatia, to international supervisors. Brcko controls the only narrow link between the eastern and western parts of Bosnian Serb territory.
The parliament speaker, Mr Petar Djokic, said: "Does the Serb Republic exist at all when its territory is cut? The process of Dayton erosion must stop."
The international community has been too stunned to react, although Brcko's international supervisor, US diplomat Mr Robert Farrand, said the town would have equality for all races. "We have finally come down to a decision on the most tortured problem of post-war Bosnia," he declared.
Anti-western demonstrations took place in the capital, Banja Luka. In the eastern town of Zvornik, a Serb crowd destroyed a Western-funded radio station.
Over the weekend, hand grenades wrecked one UN and one NATO jeep. A bomb was thrown at a Czech base in the town of Prijedor.
Meanwhile in the Yugoslav republic of Kosovo, ethnic Albanian leaders again fell out over a Western-drafted peace plan which would give them autonomy, but not full independence, from their Serb-dominated Yugoslav mother-state.
A meeting of key guerrilla commanders of the Kosovo Liberation Army to consider the deal was delayed until today because some units were trapped in fighting.
The rebels, however, having apparently agreed to accept the plan last week, are again split. One senior KLA source said powerful leaders based in Germany and Switzerland were insisting that a peace deal must include the promise of an independence referendum for the Albanian majority in three years.
This idea, rejected by both the Serbs and the West, may see the Albanians refuse to sign the peace plan today. US officials say that only when the Albanians sign can they threaten military action, including air strikes, to make the Serbians follow suit.
One KLA source said last night however that the rebels did not trust the West. They feared it would lose interest in any guarantees to Kosovo, after seeing its failures to protect civilians during Bosnia's war.