Croatian troops and tanks on Saturday rolled into Knin, the symbolic heart of the 1991 Serb insurgency, while Bosnian troops crossed the border for the first time to join in battling the rebels.
The joint offensive marked the long-feared merging of the wars in the neighboring countries and threatened to spread the fighting across the Balkans if the powerful Yugoslav army came to the aid of its fellow Serbs.Tens of thousands of Serb civilians fled the assault, crossing into Serb-held areas of neighboring Bosnia. U.N. aid officials scrambled to amass food and supplies for the biggest Serb exodus since Yugoslavia disintegrated into war four years ago.
"Nothing is going to be the same again after this," proclaimed Gen. Ivan Tolj, a Croatian Defense Ministry spokesman in Zagreb. "Any dreams about a `greater Serbia' are past."
Tolj said Croatia had achieved 80 percent of its territorial objectives in just two days.
The streets of Knin, the rebel Serb stronghold in Croatia, were virtually deserted, and large parts of town were reduced to charred rubble after two days of relentless Croatian bombardment.
"Almost the only people remaining were the dead and the dying," Maj. Alan Balfour, a U.N. spokesman, said by telephone from Knin.
At least a dozen corpses, including some women and children, lay on the streets, U.N. officials reported.
Three peacekeepers have been killed and nine wounded in the Croatian offensive, U.N. officials said.
Two Czech peacekeepers died and three were wounded after Croats attacked their observation post Saturday near Gospic, a major staging point of the offensive northwest of Knin. Elsewhere, a Russian, a Danish and a Kenyan peacekeeper were wounded. On Friday, a Danish peacekeeper died; three Poles were wounded.
NATO threatened airstrikes on Friday to protect U.N. peacekeepers, but there has been no response by allied airplanes.
With Knin under the control of tanks and infantry, Croatian forces pushed deeper into Serb-held territory, aided by their allies, the Muslim-led army of neighboring Bosnia, according to U.N. officials.
The Bosnian troops, from the northwest Bihac region, pushed west as Croatian troops pressed eastward in a pincer movement on the Serb-held Slunj area, about 75 miles north of Knin.
The linkup of Bosnian and Croatian troops at Rakovica, 11 miles southeast of Slunj, simultaneously severed northern and southern sections of Serb-held Croatia and broke the encirclement of Bihac.
Croatia and Bosnia, always tenuous allies, strengthened military cooperation two weeks ago, ostensibly to defend Bihac. But that also gave the Croatian army leave to pour thousands of troops into Bosnia, within striking distance of Knin.
Bosnian President Alija Izetbegovic congratulated Croatian President Franjo Tudjman, praising an offensive that would "ease the suffering of the population of the Bihac pocket."
Other Serb-held areas were reported falling. Croatian jets bombed three Serb-held towns south of Zagreb, including Slunj, U.N. officials said.
"We knew that we could liberate the occupied territories without provoking a wider conflict," a confident Tudjman said Saturday night in his first public comment on the offensive. "We did something fascinating, something that the world did not expect."
But Serbs in eastern Croatia struck back furiously. Heavy artillery duels raged around Vinkovci and Osijek, Croatian towns on the border of rebel-held territory in the east, U.N. officials said.
At least 40 U.N. observation posts have been either captured or destroyed in the past two days, U.N. officials said.
In an Associated Press interview Saturday, Croatian Foreign Minister Mate Granic pledged that human rights for all Serb civilians would be protected, and all former fighters except those "involved in war crimes" would be pardoned.
Serbs were unconvinced.
Overnight and early Saturday, streams of civilians and soldiers left Knin in cars and trucks, most heading northeast toward neighboring Serb-held Bosnia.
Later in the day, up to 15,000 refugees attempting to flee the Croatian offensive north of the Bihac area formed a 12 mile-long convoy of tractors, cars and trucks.
"Everybody who is able to walk wants to leave this area. They don't believe the assurances given by the Croats," said U.N. spokesman James Kanu from his base at Topusko, near two of the Serb-held towns that came under Croatian aerial bombardment.
About 20,000 Croatian Serb refugees who had earlier made it to Banja Luka, a Serb stronghold in northern Bosnia, were being directed farther east to Serb-occupied eastern Croatia.