ZAGREB, Croatia — The Croatian government declared a successful close Monday to its 3 1/2-day offensive against secessionist Krajina Serbs, officially ending one of the most lopsided campaigns in the last four years of fighting in the Balkans.
But across Croatia, as tens of thousands of Serb refugees scurried for shelter, fears grew that the military strike may have created--not prevented--new instability in the region.
U.N. officials warned of potentially calamitous humanitarian relief problems because of the mass exodus of refugees, many of whom were backed up for miles at Bosnian and Serbian checkpoints. Estimates of the number of Serbs fleeing the Krajina region have ranged as high as 150,000 to 200,000.
"This movement of population is the largest since the wars in [the former Yugoslav federation] started," said U.N. spokesman Alexander Ivanko.
About 40,000 refugees were trapped near the Croatian town of Dvor because of continued shelling in the area, the United Nations said, and five refugees in western Bosnia-Herzegovina were reportedly killed when rockets were fired from a jet at their convoy. Serb news reports blamed Croat warplanes but the United Nations could not confirm who carried out the attack.
There also were reports from Serb refugees in the area of Knin, the self-described capital of the nationalist Serbs, of Croatian soldiers shooting civilians.
Fears that more fighting may be in the offing were fueled by reports from Belgrade, the Serbian capital, that columns of Serb tanks, trucks and buses with soldiers had passed through the city in the direction of eastern Croatia. Their destination was not known. But the only remaining secessionist Serb stronghold in Croatia lies along the country's eastern border with Serbia.
The United Nations, meanwhile, confirmed that Bosnian Serb warplanes had struck at least five towns in Croatia in retaliation for the rout of the Krajina Serbs; reports from Serb-controlled northern Bosnia said soldiers were advancing toward Croatia.
At a news conference in Zagreb, Croatian Defense Minister Gojko Susak, flush with victory, sounded a non-conciliatory tone when asked about the likelihood of fighting over eastern Croatia, a prospect that Western diplomats said could draw the rump Yugoslavia, consisting of Serbia and Montenegro, into a major war with Croatia.
Susak said the weekend's lightning offensive should persuade rebel Serbs in eastern Croatia to negotiate their peaceful re-integration into the country. But he did not rule out a Croatian military grab for the territory. "Croatia will not give it up," he said. "Our estimate is that Croatia can liberate it by force if not by negotiation."
Some Western diplomats have speculated that Serbian President Slobodan Milosevic has tolerated the Croatian offensive in the Krajina only because of a tacit understanding that Serb-held territory in eastern Croatia would be left untouched. "The Croatians are understandably euphoric, but I do not believe they really think they could take on the Yugoslav army," one diplomat said.
At the evening news conference, Susak said that "Operation Storm," as the Croatians have dubbed their offensive in the Krajina, ended at 6 p.m. Monday and that Zagreb would begin demobilizing 70,000 troops today.
After two days of repeated Croatian military denials, he issued an extraordinary public reversal, confirming that the Croatian army had taken several Danish peacekeepers as human shields during its advance toward Dubica on Friday. He said that a single Croatian officer was responsible and that an investigation was under way.
Susak offered a public apology for the incident, as well as for the killing of three U.N. peacekeepers in separate incidents, but said such problems were "minimal" considering the scope of the Croatian offensive. On Sunday, Croatian Gen. Ivan Tolj dismissed the Danish complaint as an attempt to "stain the international reputation" of Croatia.
"We feel it is our duty to apologize," Susak said Monday.
In the first accounting of casualties, the Croatian government reported 118 Croat soldiers killed and 620 wounded. There has been no estimate of Krajina Serb or civilian deaths, although U.N. observers have reported seeing civilian and military casualties.
Susak also blamed the United Nations and the Krajina Serbs for a collapsed deal Monday that was to have helped tens of thousands of defeated Serbs flee into Bosnia. Croatia had agreed to allow the soldiers to leave if they left their weapons behind, but Susak said U.N. monitors of the arms drop-off showed up late, allowing many Serbs to slip out of Croatia with their weapons.
The mix-up could lead to resumed fighting in the area.
"We have been cheated and deceived," Susak said.
Meantime, in Washington, State Department spokesman David Johnson denied reports that American military advisers participated in the Croatian offensive in the Krajina.
But he confirmed that several retired American generals are working under contract for Croatia to help reorganize the country's army along democratic lines. Johnson said the contract was approved by the U.S. government.
"Some technical support is being provided to the Croatian government in helping them to establish a military that functions in a civil society, that does things like report to civil authority," Johnson explained.
The group, Military Professional Resources Inc., is based in suburban Virginia.
Times staff writer Norman Kempster in Washington contributed to this report.