VINKOVCI, Yugoslavia -- The Yugoslav republic of Croatia prepared for war this weekend as pitched battles between Serbs and Croats intensified and Yugoslav army tanks and troops sat poised on the republic's northeastern border.
Civil war in Yugoslavia has long been expected to begin in the ethnic enclaves of this region, Eastern Slavonia and Krajina, the country's most volatile ethnic flash point. Croatian officials said that in a 24-hour period, up to 83 people had been killed in intercommunal battles.
Croatian officials charge that the fighting is being deliberately provoked by armed Serbian militants, known as Chetniks, who have crossed into Croatia across the Danube from Serbia. They believe that the Serb-dominated federal army is acting in coordination with the Chetniks and plans to use the ethnic unrest as an excuse to invade the region, historically claimed by Serbia.
The area is already on a war footing. Roadblocks every few miles are manned by Croatian militiamen as well as newly formed guard units hastily uniformed in caps and armbands bearing the Croatian flag. They search every car meticulously, question every driver and demand to see identification.
Entry roads to most Serbian villages are blocked by tractors, earth-digging equipment and anything else that might help to stall the anticipated army assault.
Yesterday, fevered preparations continued. The scene in the Red Cross center in this town in northeastern Croatia was typical. Red Cross official Mato Ivancic said the center had collected emergency donations of 38 liters of blood Thursday. So far, he said, casualties had gone to hospitals in Vukovar, which was nearest the fighting, but he added that he expected casualties here soon.
Every few minutes Croatian guards and other young men arrived to collect Red Cross flags to display on ambulance cars, pharmacies and infirmaries in the town and neighboring villages. The area has a population of about 100,000 that includes 11 percent Serbs.
Mr. Ivancic described the ethnic tensions that have been building up in the region for weeks: "Everybody is now psychologically at the breaking point. People are crying. They're snappy and nervous."
He blamed the atmosphere on extremists from outside, particularly from Serbia, who had revived deep-seated ethnic hatreds between the Serbs and Croats, Yugoslavia's two main ethnic groups.
Recent events, he said, had revived memories of World War II, when Serbs in the region were massacred by fascist-leaning Croatian guerrillas called the Ustashi, and Croats were massacred by Serbian partisans known as Chetniks, the name taken by today's Serbian militants.
"Everyone here is afraid of fresh massacres," Mr. Ivancic said. "Extreme nationalist hatreds have spread to the population. It's irrational, but we are all split up.
"We even watch each other sitting on trains and listen suspiciously to what people are saying to each other," he said. "Until yesterday, we used to sit together eating, drinking and talking. Now we don't want to talk to each other."
Now, he said, "Every excursion outside is a risk, even going to work. Going by car is like going through a war zone. Every village has its own militia. You have to go through and be checked by every group."
Trains are constantly being stopped and searched by armed groups. Railroad tracks are said to be mined.
Mr. Ivancic himself is from a Croatian village of 1,700 called Slakovci. It sits next to the Serb village of Sremse Laze, with a population of 900. The villages share a school, post office, infirmary and telephone exchange. Mr. Ivancic, who taught in the school for almost 30 years, recalls no displays of ethnic hatred.
"Now barricades keep going up between the villages. Each side accuses the other of putting up the barricades first. These young men at the barricades are my former pupils. They still call me 'comrade teacher,' and the Serbs let me go through, but I can't talk sense to either side. I can't make them see that it doesn't matter who put up the barricades first; it matters who takes them down."
He blames outsiders for the situation. Serbian agents, he said, have come into the area recently to foment unrest.
The leadership of neighboring Serbia is widely believed to want to seize territory inhabited by Serbs in Croatia, to create a Greater Serbia in which all Serbs would be united.
The fear is that in order to do this, the Serbs would attempt to transform the Yugoslav army into a Serbian army. It would attempt to seize land Serbia claims in Croatia and sweep down into the republic of Bosnia and Herzegovina, where some Serbian-commanded federal army units have also been stationed during the past three days.
Until recently, Serbia had insisted that Yugoslavia remain a united federation, with central controls, dominated by the Serbs. This was in direct opposition to most other republics -- particularly Slovenia and Croatia -- which wanted the country to become a loose confederation of sovereign states. It was largely because of Serbia's stubborn opposition during months of negotiations that Slovenia and Croatia declared independence June 25.
If Serbia -- backed by the army -- does attempt to move into Croatia, however, the result is likely to be widespread, violent civil war.
Croatia maintains a well-armed militia that numbers 70,000 and has weapons ranging from Kalashnikov rifles to Singapore-made anti-tank missiles and helicopter gunships.
"Slovenia will be a Disneyland compared with the conflicts we'll have here," said Croatia's Information Minister Hrvoje Hitrec, referring to the recent fighting in Slovenia between territorial defense forces and the Yugoslav army.
Once the old, violent ethnic rivalries of Croatia and Serbia are aroused again, ethnic unrest and civil war would certainly spread quickly to other republics and ethnic groups.
Native Albanians living under repressive Serbian rule in the southern province of Kosovo have already said they want independence if Yugoslavia disintegrates. The mixed-nationality republic of Bosnia and Herzegovina is another potential flash point.