By Emily MacFarquhar

The harried parents and unruly children who crowded onto the buses beside Banja Luka's top hotel last Friday looked like typical vacationers. But this was no holiday tour, and these were no tourists. The passengers had all signed away their fixed assets and pledged never to return. The suitcases, duffels and plastic bags they were clutching contained all that remained of their worldly goods. This is the price Croats and Muslims have to pay for official permission to leave what once was Bosnia and now is part of the so-called Serb Republic. Another extortionate charge -- $ 350 a head -- is levied by the Croatian entrepreneur who runs the bus service to the Croatian capital of Zagreb as a profit-making venture.

Refugee traffic is two-way. Last week, the same buses brought a group of Serbian refugees to Banja Luka on a roundabout route from Zagreb through Hungary and Belgrade. But neither money nor documents can guarantee safe passage through the dozens of checkpoints where unsmiling men with Kalashnikovs stand ready to block vehicles at a whim. Gunmen turned back the Banja Luka convoy in yet another Serbian-controlled enclave in this crazy quilt of former Yugoslavia. Many of the would-be refugees from Banja Luka have arranged to exchange homes with the incoming Serbs. But other Muslims and Croats are so desperate to escape Serbian rule that they simply give their homes away. ''There's no life for us here," explains a young Muslim mother. ''This is the worst wave of fascism," says an engineer. Like virtually all the fleeing Muslims and Croats, she and her husband had lost their jobs.

The bus convoys between Banja Luka and Zagreb -- voluntary, peaceable, in plain view -- are the sanitized form of ethnic cleansing, the attempt to create homogeneous zones by driving away undesirable neighbors. There has been no overt violence in Banja Luka. Yet 35,000 people -- nearly 20 percent of the population -- have left the town since the Serbs took over. An additional 28,000 people in other parts of Serbian-controlled Bosnia have signed away their property and citizenship and are waiting to go. Relief officials say that 1 million people have fled Bosnia since fighting began five months ago and that hundreds of thousands more would leave if they could.

Closed borders. The sense of desperation among non-Serbs in Bosnia has mounted in recent days because next-door Croatia has announced that it is closing its border to refugees, including fellow Croats. But even those who have already crossed into Croatia cannot feel safe because the Zagreb government has also decreed that it will push back men ages 18 to 60 to make them join the anti-Serb struggle. At a sports stadium turned refugee camp in Karlovac, an hour's drive from Zagreb, Muslims who had escaped from Bosnian battle zones say their biggest fear now is that they will be separated from their families. Selin Bajric, who saw his 7-year-old daughter killed in Sarajevo, declares he will be shot before he will be torn away from his pregnant wife. On Tuesday, the 900 refugees, with their foam mattresses and meager possessions, are to be cleared out again so that the stadium can be used for police games.