The Danube is expected to peak at a record 8.65 metres (28 feet) in Budapest by Wednesday morning, but recovery will be slow and there could be more flood surges on the Danube and the more unpredictable Tisza, Prime Minister Ferenc Gyurcsany said.

No shipping is allowed on the Danube except for ferries serving communities cut off by the floods. Some schools also remained shut and a few inaccessible polling stations had to be moved ahead of Sunday's general elections.

The situation in much of the Czech Republic calmed on Tuesday after floods forced 10,000 people out of their homes over the weekend. Water levels in the country's main rivers slowly receded.

But more rain was forecast for most of central Europe, where late winter snow in higher areas could also start to melt.

"Wednesday will be a crucial day," said Ivan Obrusnik of the Czech Weather Institute.

Budapest is safe up to a river level of 10 metres, Mayor Gabor Demszky said, adding the threat remained high.

"According to the latest estimates, the total damage will exceed 10 billion forints and it will probably not be more than 30 billion (US$140 million), but that is assuming no major dams bursting anywhere," Gyurcsany said.

Polish authorities declared a flood alert in the historic northern city of Torun, where the Vistula rose a metre above alarm levels and spilled over in some areas, damaging railway lines.

A dam burst on the March river, which separates Austria from Slovakia, flooding uninhabited land, on Tuesday.

A day earlier another dam burst on the same river, flooding the village of Duernkrut and forcing the evacuation of 400 houses.