Authorities evacuated patients from the first floor of Vidin's city hospital and an orphanage, while authorities shut schools and told families with children to leave town, news agency BTA cited mayor Ivan Tsenov as saying.

In the port of Lom, home to 6,000 people, soldiers and disaster workers rushed to construct a new dyke to hold back the River, which continued rising in heavy rain and melting snow from central Europe.

"We are building a second dike in, as the water levels reach a 35-year record high of 910 centimetres," said Elena Yaneva, spokeswoman for the disaster management ministry.

The environment ministry said it expected the river to exceed 960 centimetres in Vidin on Thursday, beating a record high set in 1942 when it flooded the town. The Danube should peak at around 990 centimetres next Wednesday.

Foreign Minister Ivailo Kalfin asked Bulgaria's neighbours Romania and Serbia, which were also struggling with the floods, to reduce the flow of water pumped into the river at the hydro power complex Zhelezni Vrata, BTA said.

In Serbia, the Danube and Sava rivers were still rising near the capital Belgrade, while crews evacuated people and used sandbags to erect and shore up barriers near the Tisa river towns of Titel, Zabalj and Zrenjanin.

"We are really entering a dramatic phase in the next few days," Branislav Radovanovic of the Vojvodina water management board told live television.

In Belgrade, the Sava and Danube were 20 centimetres from record highs hit in 1981, but authorities said berms built from earth and sandbags should hold back the water when it is expected to peak on Thursday and Friday.

In Romania, over 70 houses were damaged and more than 50 people evacuated from the Danube delta village of Smardan after the river burst its banks. Some 5,000 hectares (12,360 acres) of farmland were also flooded along the river further inland.