The diplomatsstayed in Zagreb, where they were expected to meet the Croatian President, Franjo Tudjman,
"The land route the Serbs cleared, but they told us about it when we told them the plane was lifting off," Alex Ivanko, a UN spokesman in Sarajevo, said. The envoys will try again after Easter.
Although the Bosnian Serbs delivered a rude rebuff to the major powers who are seeking a peace settlement, the cancellation of the trip will notaffect the peace process, which had run out of steam already.
In Belgrade, on Tuesday, the diplomats failed to wring important concessions from President Slobodan Milosevic of Serbia. The Contact Group hadhoped he wouldforce his former clients in Bosnia to accept the peace plan. A diplomat in Belgrade admitted: "We didn't expect a breakthrough and we didn't get one."
The talks in Sarajevo were unlikely to advance the peace process. The Bosnian governmentlong ago accepted the plan and is not in a mood to agree tothe Contact Group's recent request to extend the crumbling truce, unless Mr Milosevic agrees to recognise Bosnia.
UN officials, accustomed to such treatment, were sanguine. But the diplomats in Sarajevo were bemused. "It is amazing," one Western envoy said. The Bosnian Serbs, he added, "must be the most powerful country in the world, if they can send away the big powers just like that. That [the Serbs] can do this kind of thing and that [the diplomats] take it is remarkable."
The five ambassadors are in good company. The Pope was refused entry by the Bosnian Serbs last autumn, while President Suleyman Demirel of Turkey has been turned back twice.
"There was no bitterness [from the UN], no anger, no frustration," said a Western diplomat. "It is like the closure of the airport is a natural phenomenon."
Ten minutes before the Contact Group was expected to arrive, the Serbs emphasised their discontent with the diplomatic processby firing amortar at the railway station. Seven people were injured, and air raid sirens wailed across the city. One Italian journalist was wounded when gunmen, presumed to be Bosnian Serbs, opened fire, as his vehicle waited at a French UN check-point near the airport.
The UN views with foreboding the increase in tensions around Sarajevo and Gorazde, both UN "safe areas". It fears that all-out war is becoming inevitable. Officers believe the Bosnian Serbs are massing for a counter- attack in north-east Bosnia, perhaps with help from Serbia. International monitors deployed along the border of rump Yugoslavia have reported movements of soldiers, helicopters and fuel across the river Drina, from Serbia.
These reports only emphasise the difficulty of the Contact Group's self- imposed mission. Mr Milosevic talks to them but offers nothing concrete. The Bosnian Serbs issue threats from their isolated mountain "capital". The Bosnian government issuesdemands for the Contact Group to fulfil promises to punish the Bosnian Serbs, while pursuing its own goals on the battlefields.