LIPOVA LAZNE, Czech Republic - One person drowned in southwest Poland and thousands were evacuated across the border in the Czech Republic after heavy rain continued to batter central Europe on Sunday, causing flooding in several parts of the region.

A firefighter tackling flooding in Lower Austria was also killed, Austrian Vice Chancellor Werner Kogler said on Sunday on social platform X as authorities declared the province which surrounds Vienna a disaster area.

Rivers overflowed from Poland to Romania, where four people were found dead on Saturday, after days of torrential rain in a low-pressure system named Boris.

Some parts of the Czech Republic and Poland faced the worst flooding in almost three decades and a bridge collapsed in the historic Polish town of Glucholazy near the Czech border.

In the Czech Republic, a quarter of a million homes were without power due to high winds and rain. Czech police said they were looking for three people who were in a car that fell into the river Staric near Lipova Lazne, 235 km east of Prague on Saturday.

In Poland, one person died in Klodzko county, which Prime Minister Donald Tusk said was the worst hit area of the country and where 1,600 had been evacuated.

"The situation is very dramatic," Tusk told reporters on Sunday after a meeting in Klodzko town, which was partly under water as the local river rose to 665 cm on Sunday morning, well above the alarm level of 240.

That surpassed a record seen in heavy flooding in 1997, which partly damaged the town and claimed 56 lives in Poland.

Officials in Glucholazy in Poland's Nysa county ordered evacuations on Sunday morning as local river started to break its banks and the town was cut off from power supplies. Firefighters and soldiers had been working to protect the town's infrastructure since Saturday but that failed to prevent the bridge collapse.

Local police announced plans for people trapped in flooded houses in Nysa county to be rescued by helicopter.

Residents across the Czech border also said the situation was worse than flooding seen before.

"What you see here is worse than in 1997, and I don't know what will happen because my house is under water, and I don't know if I will even return to it," said Pavel Bily, a resident of Lipova Lazne.

The fire service in the region said it had evacuated 1,900 people as of Sunday morning, while many roads were impassable.

In the worst hit areas, more than 100 mm of rain fell overnight and around 450 mm since Wednesday evening, the Czech weather institute said.

More rain is expected on Sunday and Monday.

In Budapest, officials raised forecasts for the Danube to rise in the second half of this week, to above 8.5 metres, nearing a record 8.91 metres seen in 2013, as rain continued in Hungary, Slovakia and Austria.

"According to forecasts, one of the biggest floods of the past years is approaching Budapest but we are prepared to tackle it," Budapest's mayor Gergely Karacsony said.

In Romania, authorities said the rain was less intense than on Saturday, when flooding killed four and damaged 5,000 homes. Towns and villages in seven counties across eastern Romania were affected, and the country's emergency response unit said it was still searching for two people missing.

  - Reuters