Undated (AP) _ By TONY SMITH Associated Press Writer

VUKOVAR, Yugoslavia (AP) - On Sunday, when the Yugoslav army attacked Vukovar Hospital, Miloslav Lipovcevic's daughter Jasna was in labor.

She gave birth to a son, Hrvoje, scooped up the infant, and rushed - as everybody now does in Vukovar - to the basement.

Federal air force jets bombed the city on Sunday, and people injured in Croatia's secessionist war now are being cared for in the hospital basement, crammed along corridors and among makeshift toilets and kitchens.

Civilians venture into the streets only in daylight. On Friday, about 50 people lined up for bread, then shared it among themselves with the quiet patience that comes of common suffering.

At night, they cower in cellars.

Vukovar, in eastern Croatia's Slavonia region near the border with Serbia, has been the scene of fierce fighting between Croatian militiamen and ethnic Serb militants since last Saturday.

The fighing has left Vukovar's central square, market and shopping area in ruins. The city museum, a Baroque palace dating to 1750, has had a wing lopped off.

At No. 86 Ive Lole Ribara St., on the Danube River, Josip Kis is responsible for getting everyone into the basement when the air raid sirens sound.

''This is just a lull in the fighting,'' Kis told reporters who managed to enter Vukovar using dirt roads when the gunfire briefly halted on Friday. ''It could start again at any time. We've heard (troops) are coming from Belgrade now.''

Asked about the federal army, which Croatia says is helping ethnic Serb rebels, Kis swore and said bitterly: ''We paid for those grenades they're now shelling us with.''

The Yugoslav army has insisted it is only trying to separate warring Serbs and Croats. But on Thursday a European Community official who traveled to Yugoslavia to gain agreement for a peace proposal said it was clear that the army had sided with the Serbs.

Before Croatia declared independence on June 25, Vukovar had about 80,000 residents - 36,000 Croats, 31,000 Serbs, and the rest ethnic Hungarians, Ruthenians, Slovaks and others. No one knows how many residents now remain.

Some have fallen in the fighting. Of the 61 civilians and 44 Croatian security forces brought to the hospital wounded this week, 16 died. Ten were civilians.

Lipovcevic, a nurse caring for the wounded in the hospital basement on Friday, told a visitor about his grandson's birth in the midst of battle. It illustrated, he said, how the fighting has transformed every aspect of life in Vukovar.

Dr. Juraj Njavro, a Croat from the central state of Bosnia-Hercegovina, said he has been a casualty surgeon for 23 years. But his experience did little to prepare him for an assault that damaged two of the hospital's four operating rooms, shattered dozens of windows and left walls riddled with holes from bullets and grenades.

Miraculously, bandages and drugs are still arriving from Zagreb and Slavonia's capital, Osijek, 24 miles to the northwest.

Operations have been moved from the second to the ground floor. But Njavro worries about cramming patients into the basement and the spread of infections.

Darko Munjekovic, the 23-year-old president of the Osijek Students' Union, lay in the basement Friday with a bullet wound in his left leg and fractures in both arms and legs. He joined Croatia's National Guard just after independence was declared.

''This is a strategic town,'' he said. ''I think they'll try to take it. I don't know if we can defend it - I'm a law student, not a soldier.''

Last Saturday, Munjekovic was in a corn silo in the Croatian-dominated hamlet of Borovo Naselje, six miles north of Vukovar, when armed Serbs and the army attacked.

Power was cut, so Munjekovic could not use the silo elevator to escape. One stairway was destroyed, so he raced down another. A bullet hit his leg, and he fell 25 yards.

Munjekovic says he will fight again after he recovers. Like the Serbs on the other side of the fighting in Slavonia, he believes he is defending his homeland.

Njavro, the surgeon, said people of many ethnic backgrounds have been caught in the fighting in Slavonia.

''A lot of Serbs, Ruthenians, Hungarians ... are also suffering,'' he said. ''They've been forced into this war, and are paying for Croatian freedom in blood.''

Ruzica Caljekusac walked down the main street carrying a basket of pink and yellow roses for the makeshift home she has made in her cellar.

''This is a symbol of how I want to live - normally,'' said the 35-year-old Croat. ''My apartment always has flowers.''

DT