Rising floodwaters forced the evacuation Sunday of more than 1,400 people in southeastern Germany, including residents of two homes for the aged, authorities said.

After three people drowned Saturday in a cellar in Neunkirchen near the city of Chemnitz in a flash flood, police warned that a heavy downpour posed a threat to residents throughout the region.

"It is still raining hard and there is no let-up in sight," said a spokesman for disaster management in the city of Goerlitz, which lies on the Neisse River dividing Germany from Poland, about 150 kilometres (90 miles) to the east of Chemnitz.

Authorities said 1,450 residents of Goerlitz and the surrounding area had been taken to safety in boats, buses and helicopters.

Heavy rains and a dam-break on Witka Lake in Poland near the German border led the Neisse and several other rivers in Germany, Poland and the Czech Republic to burst their banks, German authorities said.

"Flash floods hit the city within a few hours and there was nothing we could do to prepare ourselves," Goerlitz Mayor Michael Wieler told news channel N24.

The extreme weather in central Europe has claimed the lives of at least eight people including four in the Czech Republic and one in Poland.