Croatia Takes 2 Towns in Bosnia From Serbs : Balkans: U.N. sees threat of wider war in fighting across borders. Road links between rebels are severed.

A powerful Croatian army force seized key crossroads towns from rebel Serbs on Friday in cross-border fighting that the United Nations and NATO experts warned could ignite a wider war in the Balkans.

The Croats, who went into Bosnia-Herzegovina earlier this week, captured the Bosnian town of Bosansko Grahovo. That severed road links between Serb-controlled areas of Croatia and Bosnia and threatened supply lines to Knin, the city in southwestern Croatia that Croatian Serb rebels consider their capital.

Sources with the North Atlantic Treaty Organization said the Croats were within five miles of Knin itself Friday night after fighting that chased thousands of civilian Serbs from their homes. “The situation is extremely tense. All the preparations are there for a wider war,” said one senior NATO official here.

Friday night, Croatian sources reported the capture of the town of Glamoc, 25 miles southeast of Bosansko Grahovo near the Croatian border.

The Croatian assault was riposte to an attack by rebel Serbs from Croatia on the Muslim enclave of Bihac farther north, in western Bosnia. U.N. officials said the Croats are determined to relieve pressure on Bihac, where 160,000 or so people are trapped by Serbian forces from Bosnia and Croatia.

Amid fresh attacks and shelling in the Bihac pocket Friday by nationalist Serbs, U.N. relief officials said food warehouses were empty in the town of Bihac, where the situation was described as desperate.

With the consent of the Bosnian government, the Croatian army and Bosnian Croat militias now have up to 10,000 troops massed in the Livno Valley area of western Bosnia, said U.N. spokesman Chris Gunness.

“It’s a serious and alarming buildup. In Croatia, we fear that military actions may be initiated soon, possibly within days,” Gunness said.

Croatian television said the force had captured 85 square miles or so of territory. Kris Janowski, spokesman for the Office of the U.N. High Commissioner for Refugees, said that about 5,000 civilians had fled the Bosansko Grahovo area to Drvar, where they were being housed in collection centers, sports stadiums and a hotel.

Reacting to the Serbs’ reverses Friday, Bosnian Serb leader Radovan Karadzic proclaimed martial law and ordered a full mobilization; so did Croatian Serbs.

Cutting the supply route between Serb-controlled areas of Croatia and Bosnia puts the Croats in a better position for any eventual attack on Knin and offers them a potential springboard for assaults on other Serb-held chunks of Croatia captured in the 1991 Serb-Croat combat.

Friday’s developments came as the United States and its major allies prepared for a NATO meeting early next week still sharply divided over an American proposal to extend the threat of air strikes to help protect other U.N.-designated “safe areas” besides the eastern enclave of Gorazde.

The Clinton Administration has been pressing for action by NATO this weekend, arguing that the allies should complete groundwork for any such action in case Bosnian Serbs attack the Bihac enclave.

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But Western officials said that Britain still is not prepared to sign on to the plan, despite heavy lobbying by the United States, and that some of the smaller countries in the 16-nation alliance remain skeptical as well. Officials said Secretary of State Warren Christopher made an unsuccessful last-minute appeal to NATO Secretary General Willy Claes on Friday to speed action on the proposal.

Christopher said that NATO’s policy-setting North Atlantic Council will convene in Brussels on Monday to consider the expansion, after a Sunday meeting in which NATO force commanders are expected to complete details of a military plan.

White House Press Secretary Mike McCurry said the Administration has urged all factions in the Balkans to “exercise restraint.” He added that “we are aware” that the Croats are formally allied with the Bosnian Muslims and that the Muslims asked for their help.

Serbs revolted when Muslim Bosnia and Roman Catholic Croatia seceded from the then-dissolving federation of Yugoslavia. War has been waged unendingly across Bosnia, but a cease-fire has been generally in effect in Croatia since January, 1992. Now the fear is that war in Croatia could flare anew and blend with the Bosnian struggle into an ever larger blaze.

Attacking west of Bihac on Friday, Croatian Serbs advanced behind a withering artillery barrage--more than 1,000 detonations were counted in one hour Friday morning by U.N. observers.

Control of Bihac would give rebellious Serbs in Bosnia and Croatia claim to a swath of territory extending to the Serbian border, advancing their dreams of creating a Greater Serbia.

Croatian Serbs crossed into Bosnia last week to mount their assault on Bihac, while international attention was focused on the eventually successful assault by Bosnian Serbs on the eastern Bosnian enclave of Zepa.

When they crossed the frontier from areas they control inside Croatia into Bosnia to attack Bihac, Croatian Serbs violated international law, U.S. Ambassador to Croatia Peter W. Galbraith said in an interview Friday.

“In attacking across an international border, the rebel Serbs have put themselves in a very perilous situation,” he said. Croatia has an international right--and obligation--to restrain the attackers. Croatian troops, he noted, entered Bosnia legally at the behest of the Muslim-led but non-sectarian Bosnian government.

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Reacting to the international failure to halt the Bosnian Serb conquest of U.N.-declared “safe areas” in Srebrenica and Zepa, the Bosnian and Croatian governments agreed last Saturday to increase military cooperation, particularly with regard to defending Bihac.

In Zagreb, NATO officials said that Croatia is resolved not to allow Bihac to fall. But in pressing their own hopes of recovering territory from rebellious Serbs, the Croats must keep a wary eye on Belgrade, where the Serbian government is the ultimate ally of its rebellious cousins in Croatia and Bosnia.

Indeed, in action that was intended to impress Croatia, there was movement of Serb-controlled troops and tanks Friday near Vukovar in eastern Croatia, the officials noted. The key question to be resolved in coming days, then, is whether Croats will attempt to capture Knin at the risk of Serbian displeasure. Croatia says not, but not everybody is convinced. “I wouldn’t bet the ranch against it,” one senior NATO official said.

Meantime, in Washington, the Administration braced for another Balkan-related onslaught from Capitol Hill as Republicans announced that the House will speed action on a Senate-passed resolution to lift the arms embargo against participants in the Bosnian conflict, taking it up early next week.

Rep. Benjamin A. Gilman (R-N.Y.), chairman of the House International Relations Committee, said sponsors probably will be able to garner enough votes to override a presidential veto. Clinton has warned that he will reject the measure if it is passed.

Proponents of the measure contend that the embargo most hurts the Bosnian government because its forces are generally less well armed than their Serbian foes, who gained access to the ordnance of the federal Yugoslav army.

Times staff writer Art Pine in Washington contributed to this report.

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Battle for Western Bosnia

Croatian soldiers swept north along the Bosnian border to capture Bosansko Grahovo. Fifty miles away, Croatia’s rebel Serbs pounded Bosnian troops in Bihac. The United Nations says it may be too late to keep the rebellions from merging into a single war.

Rebel Serbs from Croatia gained ground in an assault on Bosnian troops in Bihac.

Croats capture Bosansko Grahovo, offering a possible springboard for attacks on Serb-held Croatia.

Croatian Serb stronghold.

Source: United Nations