Bosnian Serb forces reportedly closed in on the last Muslim-defended stronghold in eastern Bosnia, battling at close range for control of Gorazde.
At least 52 people were killed Sunday when shells slammed into a makeshift hospital in Gorazde (pronounced goh-RAZH-deh), Bosnian radio reported.
The city is one of the six U.N.-declared "safe areas."
"No one survived. . . . The place is now a mixture of pieces of dead bodies, bricks and plaster," said ham radio operator Fahrudin Becic.
Bosnian radio said 59 people were killed and more than 100 were wounded. It said troops from both sides suffered heavy losses.
Gorazde, home to up to 70,000 residents and refugees, has been cut off for months and under fierce attack for 17 days. Bosnian Serb leaders have refused to allow U.N. monitors into the town.
Gen. Philippe Morillon, the U.N. commander in Bosnia, repeated his demand Sunday that Serbs admit observers. He said the U.N. Protection Force in Bosnia would "have no option but to withdraw" unless it gets full cooperation from all sides.
In Geneva, Bosnia's seven-man collective presidency, which consists of Croats and Serbs as well as Muslims, demanded the immediate deployment of U.N. peacekeepers in Gorazde to help stem the bloodshed, said Bosnian Vice President Ejup Ganic.
The presidency also issued an order in Geneva urging Muslim and Croatian forces to stop their fighting in central Bosnia as Muslim and Croatian leaders met to consider power-sharing arrangements.