The demilitarisation, proposed by the UN commander in Bosnia, Lieutenant-General Sir Michael Rose, would in effect give Serbs a free hand to prosecute attacks elsewhere in the Bihac pocket, home to 180,000 people, without UN interference.
''There was a demand yesterday by the [UN] Security Council for an immediate and unconditional ceasefire in the region. We accepted that,'' said Haris Silajdzic, the Bosnian Prime Minister. ''There was a call today to demilitarise. We accepted that. But since we are afraid this is another ploy by the Serbs to buy time, we have said that if by tomorrow midnight they do not accept it, the UN and Nato should immediately call air strikes, because all other avenues have been explored.''
The latest developments exposed once again the rift between the US and its Nato allies over Bosnia. Bob Dole, the Senate Republican leader, yesterday called the international effort to end the war a ''classic failure'' and called for the UN peace-keeping mission to be terminated.
The US Defense Secretary, William Perry, also conceded the Serbs had in effect won the war and Nato air power could not change that. He added that he saw ''no prospect'' of the Bosnian government winning back any of the 70 per cent of the country held by the Serbs.
Under the three-point UN proposal sent simultaneously to the Bosnian government in Sarajevo and the Bosnian Serbs in Pale, both armies would withdraw from the ''safe area'' and the UN would place its forces in ''sensitive locations''.
UN officials said Bosnian troops were ''down to their last slender lines of defence'' in Bihac. Fighting continued in the safe area yesterday, and the UN said the combined force of rebel Serbs from Bosnia and Croatia was close to encircling the town, north of the safe area limit.
Two UN officials in the enclave described the fear and desperation in the town. ''The Serbs can just sit and shell away. They are encroaching on the built-up area. To all intents and purposes they are in the town,'' said Ed Joseph, a civilian official. Monique Tuffelli, an aid worker, said explosions were audible from the hospital, where Bangladeshi peace-keepers are attempting to create a protective shield.
The UN officials said people felt there was nowhere to run. ''There is a bizarre atmosphere of anguished waiting, a deep resignation strangely allied with the abiding hope that Bihac in the final analysis will not be allowed to fall,'' Ms Tuffelli said.
''How could they go somewhere else which did not even have the paper status of a 'safe area'?'' asked Mr Joseph. ''They know they're not protected. They're prepared to die.''
If the Rose proposal is accepted by both sides, the 70,000 people in Bihac should survive, protected by the UN. But 110,000 civilians elsewhere in the pocket could be even more vulnerable. The general yesterday called ''urgently for the demilitarisation of the designated Bihac safe area in order to safeguard the civilian population'' - something the UN has failed to do, despite its mandate to deter attacks on safe areas.
General Rose also warned that peacekeeping troops might be forced to withdraw from Bosnia if fighting intensified.
Yesterday, another 150 soldiers - British and Dutch - were detained by Serbs as they tried to leave Serb-held areas. At least 250 of their comrades have already been held for several days, in an apparently successful attempt to avert Nato retribution.
UN, Nato dilemma, page 9
What could die at Bihac, page 15