Sarajevo Threat Is Apparently Defused : Yugoslavia: Serb leader first says followers are marching on city. Then he calls on them to stay at home.

SARAJEVO, Yugoslavia — After a Serbian vigilante action failed to set Bosnia-Herzegovina’s tense nationalities against each other, Serbian radicals called on Serbs on Tuesday to advance on the capital in a move that threatened civil war.

But Serbian Democratic Party leader Radovan Karadzic said early today that he has appealed to his followers to remain in their own communities, a conciliatory gesture apparently prompted by warnings from the Yugoslav federal army.

Karadzic had said a few hours earlier that Serbs were marching on the capital, and heavily armed Muslim police guarding the city’s center said they had been told that 2,000 Serbs were headed their way.

Emergency talks involving Karadzic, regional army commander Gen. Miodrag Kukanjac and Bosnian President Alija Izetbegovic produced a shaky agreement to jointly patrol the city; all parties appealed to their supporters to go home and remain calm.

The contradictory actions by Karadzic appeared to be the maneuvers of a desperate politician.

Karadzic’s party had backed an armed uprising by Serbs late Sunday that threatened to spark widespread ethnic conflict but was defeated by a peaceful student protest. Karadzic, who was in the Serbian capital of Belgrade when his supporters sealed off Sarajevo with at least 20 barricades, suffered a huge loss of prestige and influence because of the incident.

Moderate Serbs in Sarajevo were outraged by the armed action aimed at derailing a democratic vote for independence. And even hard-liners opposed to secession were upset by the militants’ defeat at the hands of unarmed students.

Izetbegovic warned his republic late Tuesday that armed Serbs were advancing on the capital and appealed to them to return home. “Serbs can peacefully sleep. No one is going to attack them,” the president, who is Muslim, said in a television address. “I beg you to stay at home. Do not attack anyone.”

He then summoned Karadzic to a meeting at Yugoslav army headquarters in the city, after which the Serbian leader greatly softened his tone. Karadzic told journalists before the meeting that Serbs had been called on to surround the capital, then two hours later denied that he had said that and called Izetbegovic’s claim of a Serbian threat “a terrible lie.”

Earlier Tuesday, Izetbegovic had praised Sarajevo’s triumph of tolerance over terrorism, saying the Serbian gunmen who had held the city hostage for 24 hours by putting up barricades had been defeated by the majority’s will for peace. “Sarajevo will never be blocked in the future,” he vowed. “I can’t say whether this could happen in other areas. There are those who want to take advantage of tensions.”

But the spontaneous outpouring of 5,000 demonstrators that helped drive away the armed Serbian militants late Monday was just a hint of the public uprising that would be sparked by any future incident of the kind, Izetbegovic said.

“These things cannot be repeated in Sarajevo,” the president said of this integrated city where Muslims, Serbs and Croats have long lived together in peace. “If it does, we will call on the citizens to stop it, and 200,000 would come out.”

The barricades that paralyzed Sarajevo on Monday were put up to protest a two-day referendum approving Bosnian independence, although Karadzic blamed the incident on what he claimed was a “political murder” at a Serbian wedding party on Saturday.

Many of Bosnia’s 1.4 million Serbs oppose secession from Yugoslavia, since that would politically sever them from the republic of Serbia. The Serbian Democratic Party advised supporters not to participate in the referendum, but well over 60% of the voting-age public cast ballots in favor of independence, nullifying the effects of the boycott.

The barricades were removed late Monday, after the militants were confronted by two groups of student demonstrators, some carrying bread and children to underscore their peaceful intentions.

The first group was fired on and suffered casualties, but the gunmen withdrew as the second, larger force approached.