Authorities evacuated 3,200 people and more than 6,000 animals from the village of Rast in southern Romania on Monday after the Danube breached a nearby dam and flooded the area.

"Police and paramilitary units used trucks to take people out of the flooded village. They have been taken to stay with relatives or friends," said police spokeswoman Maria Vasile.

In the nearby village of Negoi, 230 people were taken to safety. Television footage showed police in rescue boats helping people to escape from their houses.

Elsewhere in Romania, authorities employed controlled flooding at the weekend to slow the river's rise and in some places its level dropped.

But officials said a wave of floodwater travelling down river from Serbia would reach Romania in coming days and that hundreds more people were ready to evacuate at a moment's notice.

ALERT TO SAVE LIVES

More than 44,000 hectares in southern Romania, a fertile region for wheat and maize farming, are under water and officials said they would submerge another 26,000 hectares this week to help protect heavily populated areas.

"We are on alert and doing what we can to prevent damage and to save lives," said Chirica Lefter, government representative for Romania's Tulcea county.

Much of the region is still reeling from floods last year in which scores of people were drowned and houses, farmland and infrastructure worth hundreds of millions of euros (US dollars) were destroyed.

In Serbia's capital Belgrade, 250 km of flood defences held the Danube at bay as it reached record levels, but officials said there was a danger waterlogged dykes could collapse.

The Tisa river also hit a record level, just centimetres below the top of embankments.

"We now have to watch out for the long-standing pressure on the barriers, with water expected to stay high for some 10 to 15 days," said Goran Kamcev, head of Serbia's anti-flood task force.

"It could cause the dykes to leak or even break and our teams on the ground have to stay vigilant."

Officials said heavy flooding had been reported in Ritopek, downstream from Belgrade, and people in the area had asked for sandbags.

In the port of Vidin in northwest Bulgaria, the river dropped slightly but more than 100 people fled for dry ground from the town and and from Nikopol downstream. Many of Nikopol's houses were submerged.

Civil defence workers prepared to evacuate 600 people from the village of Zabovanovo because they expected the Danube to rise again.

"A new high wave is expected this Wednesday and there may be new flooding," said Georgi Linkov, civil defence head in Pleven, northern Bulgaria.