SARAJEVO, BOSNIA-HERZEGOVINA — IGNORING devastating reports of atrocities against Muslim refugees, Bosnian Serbs are threatening Western powers not to defend the five remaining cities in Bosnia that are declared ''safe zones'' by the United Nations.
Bosnian Serb leader Radovan Karadzic warned yesterday his men would shoot down any foreign planes that came to the aid of Muslims in other safe areas. Now, as more safe zones are threatened, tens of thousands of refugees are finding they have nowhere to turn.
The 42,000 people in the safe zone of Srebrenica were sent on the run July 11 when Bosnian Serb forces stampeded into the city. Most of them were already refugees from other areas the Bosnian Serbs had conquered earlier, and they knew their lives were in danger.
Some 20,000 people fled to the Dutch UN base in Potocari, about three miles north of Srebrenica, as Serb forces fired over their heads. They camped around the UN base in abandoned factories, fields, barns, and whatever they could find.
The next day, the infamous Bosnian Serb general, Ratko Mladic, showed up with a hundred buses and Bosnian Serb television cameras in tow, telling the hungry and tired refugees to board. ''I won't take no for an answer,'' he was reported to have said.
To show the world he was not the war criminal he has been accused of being, he brought chocolate for the refugees. With TV cameras rolling, Mladic patted young boys on the head and announced that refugees and prisoners of war would be treated according to the Geneva Conventions.
Then with TV cameras turned off, his men boarded the exhausted refugees on the buses and dumped them a mile from the confrontation line and made them walk through no-man's-land into government-held territory. Many of the women claimed they were raped by Serb soldiers during the trek. Others simply disappeared.
Officials from the United Nations High Commissioner for Refugees (UNHCR) said the refugees were accompanied only by Serb soldiers during the journey. ''They are totally in the hands of the Serbs, and we have no way of knowing what happens to them,'' said UNHCR spokesman in Sarajevo Kris Janowski.
After just three days, the Bosnian Serbs had managed to empty out the entire pocket of 42,000, stalling the International Committee for the Red Cross and UN aid convoys from entering the area. Serb radio reported that anyone who stayed behind to fight was either ''taken prisoner'' or ''liquidated.''
By the weekend, the UN reported that 23,000, mainly women, children, and elderly had been bused out of the Srebrenica enclave by the Serbs and had arrived at a makeshift UN camp in Tuzla. The fate of thousands of others was unknown. ''God knows how many are still left in Srebrenica and what their fate is,'' says UN spokesman Janowski.
From the horrendous conditions at the camp at the Tuzla air base, the refugees began to tell their stories. Women said their husbands, sons, and boyfriends were torn from their families. Some said the men were killed before their eyes. Others said they simply did not know what became of their men. Many said they saw corpses lying next to burning houses. They said young women were dragged away on the buses.
The reports are thus far uncorroborated because journalists, human rights workers, and UN personnel have been denied access to Srebrenica. ''The information we have has been gathered through random interviews,'' said the UNHCR spokesman in Tuzla, Fernando del Mundo. ''But we have heard so many stories of rape and abduction.'' Mr. Del Mundo said a team from the UN Commission on Human Rights had arrived in Tuzla and was beginning an investigation.
But a measure of relief for the refugees came by way of a report from the Bosnian Army that nearly 6,000 of the15,000 people feared missing or dead after the Bosnian Serbs took Srebrenica had started pouring into Bosnian government territory.
The column of people, mostly men, had fought their way past advancing Serb forces and escaped past the front lines. They made their way through the woods for eight days through mine fields and intense shelling. They said there were some massacres along the way and many were killed, Del Mundo said.
Some reported seeing Serb soldiers in UN uniforms, driving white UN tanks. The rebel soldiers disguised as peacekeepers reportedly lined up a group of Muslim refugees and executed them with machine-gun fire.
The men, in rags, reported eating grass and bugs to survive. They said some in their column went insane and ran directly into Serb firing lines to be slaughtered. Thousands of Srebrenica's inhabitants are still unaccounted for. UNHCR was bracing itself for another flow of refugees from Zepa, where Bosnian Serbs stand poised to overrun that enclave.