Intense Attack by Serbs Triggers 2nd NATO Raid : Bosnia: Assault on enclave of Gorazde continues after bombing run, then stops. Rebels block U.N. troops in Sarajevo and break off contacts with mediators.

Serbian rebels, angered by a NATO air attack, provoked a second bombing raid Monday by defiantly intensifying an artillery assault on the city of Gorazde, barricading U.N. troops in Sarajevo and severing contacts with mediators trying to broker peace.

Serbian tank and artillery fire on the densely populated eastern city that is a U.N.-designated “safe haven” continued even after two U.S. jets bombed rebel artillery positions for a second day.

The air strikes destroyed one Serbian tank and damaged two others, Maj. Dacre Holloway, a U.N. spokesman, said after the American F/A-18s dropped three bombs on the rebel position at 2:19 p.m.

But the Serbs continued to bombard the mostly Muslim enclave of 65,000, inflicting the heaviest casualties on the civilian population since the offensive began two weeks ago, according to U.N. officials and Western relief workers in Gorazde. Later in the day, however, the Serbian attacks stopped.

A French physician from the international relief group Doctors Without Borders told reporters here in a ham radio exchange that 62 had been killed in the previous 24 hours, bringing the two-week death toll to more than 150.

The unrelenting attack prompted British Lt. Gen. Michael Rose, the U.N. commander for Bosnia, to threaten further reprisals unless the belligerence stopped speedily. “You’ve got 10 minutes or you get it again,” Holloway quoted Rose as telling Serbs in his final warning.

The last heavy-artillery shell reported by U.N. monitors in the besieged pocket landed at 4:09 p.m., said Maj. Rob Annink, chief spokesman for the 13,000-strong U.N. mission in Bosnia. That was about 25 minutes after Rose’s ultimatum, and shells continued to fall farther south for an hour longer, other U.N. sources reported.

The defiant posture of the rebels, who massively outgun the Bosnian government forces but present a pitiful match for NATO, suggested a deadly showdown may be in the offing between the Serbian nationalists, who have conquered 70% of Bosnia, and the Western powers that have long relied on diplomacy in their frustrated effort to stop the war.

The Serbian actions were a coordinated effort at belligerence after the first deadly air strike Sunday and demonstrated that the rebels were not yet prepared to back down.

Gunmen loyal to Bosnian Serb leader Radovan Karadzic and Gen. Ratko Mladic, his fiercely nationalist military commander, erected barricades across the sole access road to Sarajevo airport and barred U.N. personnel, diplomats and foreign journalists from entering or leaving the city.

All humanitarian relief flights and aid convoys were suspended as a security precaution, but an official of the Office of the U.N. High Commissioner for Refugees in Sarajevo reported what appeared to be deliberate targeting of the relief agency’s staff and facilities in Gorazde. One shell landed so close to the U.N. refugee agency office that it blew the windows out and sent the staff running for cover in basement shelters, said agency spokesman Kris Janowski.

The 13 U.N. military personnel in Gorazde also came under sniper fire from Serbian positions and were forced to take cover in their bunkers, U.N. sources said.

A statement issued from Karadzic’s mountain stronghold in Pale, about 10 miles east of Sarajevo, said the Bosnian Serbs were breaking all contacts with the U.N. Protection Force.

The only remaining channel of communication with the rebels appears to be Russian Deputy Foreign Minister Vitaly S. Churkin, who met with Serbian leaders in Belgrade and then headed for consultations with Karadzic and Mladic.

Churkin expressed confidence after his talks with Serbian President Slobodan Milosevic that he can rescue the negotiations aimed at an overall peace settlement in Bosnia. He offered an implied criticism of the Bosnian Serb hard-liners for escalating the Gorazde offensive to crisis proportions.

Churkin, Russia’s special envoy for the troubled Balkans, echoed Russian President Boris N. Yeltsin’s criticism of the NATO air actions, saying they were conducted without appropriate consultation with Moscow. But he conceded that the Western alliance had been provoked into embarking on the “slippery slope” of intervention.

Milosevic, seen as the mastermind of the Greater Serbia campaign that has kept the Balkans in conflict for the past three years, publicly lambasted the U.N. resort to air strikes as “shattering the illusion of international impartiality over Bosnia.” He accused the U.N. Protection Force of intervening on behalf of the Bosnian Muslims, who have suffered the brunt of the war’s casualties and displacement at the hands of Serbs.

Momcilo Krajisnik, head of the rogue Bosnian Serb Parliament, denounced the air strikes as “a great blow to peace.” Another rebel hard-liner, Biljana Plavsic, described the United Nations as an aggressor against the Serbs.

“The peace process is in danger and full responsibility lies with the U.N.,” said a Serbian statement carried by the Yugoslav news agency Tanjug. “The Serbs will not be intimidated and will retain the right to self-defense using all available means.”

Charles Redman, special U.S. envoy for the former Yugoslav republics, conceded that the negotiations he, Churkin and U.N. officials have been mediating will be on hold until the crisis in Gorazde is calmed.

U.N. spokesman Annink defended the U.N. actions. “We have shown restraint and also shown the Serbs what we could and would do” if they persist with the offensive, he said.

Sarajevans praised the air strikes as a warning to Serbs that their deadly rebellion must stop, but they complained bitterly that the intervention, two years after the insurgence began, has arrived too late for the 200,000 killed in the war. “It has come very late, but in any case it is worth it,” said Ahmed Novo, a young Sarajevo doctor enjoying a rare day off at a cafe with his girlfriend. “It is important that the international community show that this aggression has to be stopped.”

In a ham radio communication between Gorazde and the Bosnian presidency building here, Gorazde city official Esad Ohranovic described Monday’s shelling as “the worst day” of the war. Serbian gunmen, having advanced in tanks and armored personnel carriers, were fighting with troops of the Muslim-led government hand to hand in the southern suburbs of the city, Ohranovic said.

But he described the population as relieved after the first air strikes and uplifted by the second demonstration that the United Nations is serious about forcing the Serbs to stand down.

“There was a kind of celebration; everyone was very happy but worried about the day after,” Ohranovic said of the atmosphere in Gorazde after Sunday’s attack. “What happened this morning proved nothing was solved. After the second air strike, all the people were very happy.”

The bombardment remained unrelenting, with shells falling as rapidly as one every few seconds, until rain and low clouds deprived the Serbs of the advantage of artillery cover from afar. NATO planes buzzed the Serbian artillery positions repeatedly throughout the day and fired illuminating flares at the rebel armor as part of an escalated series of warnings before the air strikes.

U.N. officials said after nightfall that Mladic had conveyed to Rose his assurances that the Serbian offensive was over. Similar promises that the shelling had stopped were also issued before and after the first air strikes Sunday, in which as many as 15 Serbian fighters were reported to have been killed or wounded.

Drawing The Line

Considered the chief aggressors in the 2-year-old war, the Serbs are determined to carve out large sections of Bosnia, particularly in eastern Bosnia, which borders Serbia proper, to create a “Greater Serbia.” The air strikes reflect the international community’s resolve not to let this happen.

SUNDAY

1) F-16s attacked command post and artillery sites.

MONDAY

2) F-18s used 20mm cannon and MK-82 bombs to strike Bosnian Serb positions, southwest of town.

Bosnian Serbs control all but these 3 areas in eastern Bosnia. Gorazde would help bid to create “Greates Serbia.”