A low-pressure system named Boris has triggered downpours from Austria to Romania, leading to some of the worst flooding in nearly three decades in hard-hit areas in the Czech Republic and Poland.
More rain and strong winds are forecast until at least Monday (local time), though the rain eased on Sunday in Romania, which bore the brunt of flooding a day earlier.
Thousands of homes have been damaged over the weekend, bridges swept away and at least 250,000 households - mainly in the Czech Republic - were affected by power cuts.
One person drowned in southwestern Poland on Sunday, a firefighter taking part in rescue efforts was killed in Austria and two more people were killed in Romania, where the floods claimed four lives on Saturday.
In Lower Austria, the province surrounding Vienna where government officials said the firefighter had died, authorities declared the area a disaster zone and warned against non-essential travel.
A bridge collapsed in the historic Polish town of Glucholazy near the Czech border and local officials ordered evacuations early on Sunday. Local media said another bridge collapsed in the mountain town of Stronie Slaskie, where a dam burst, according to the Polish weather institute.
Polish Prime Minister Donald Tusk, who visited nearby flooded areas, said on the X platform the government would announce a state of disaster and seek European Union aid.
'UNDER WATER'
In the neighbouring Czech Republic, police said they were searching for three people who were in a car that plunged into the river Staric on Saturday near Lipova-lazne, a village about 235km east of the capital, Prague. Rainfall in the area has reached about 500mm since Wednesday.
Reuters footage showed flood waters gushing through Lipova-lazne and neighbouring Jesenik, damaging some houses and carrying debris.
"We don't know what will be next," said Mirek Burianek, a resident of Jesenik. "The internet network isn't working, telephones don't work ... We are waiting for who will show up (to help)."
Lipova-lazne resident Pavel Bily told Reuters the floods were even worse than those seen in 1997. "My house is under water, and I don't know if I will even return to it," he said.
Residents in some flooded areas were bracing for conditions to deteriorate.
"When it rains (in the nearby mountains), it will arrive here in five or six hours," said Ferdinand Gampl, an 84-year-old resident of the village of Visnova, 138km north of Prague.
Emergency services used a helicopter to evacuate people stranded in the Lipova-lazne district. Overall, more than 10,000 people had been evacuated in the country, the head of the fire service told Czech television.
In the Hungarian capital, Budapest, officials raised forecasts for the river Danube to rise in the second half of this week to more than 8.5m, nearing a record of 8.91m in 2013.
As the rain eased in Romania, workers sought to restore power supplies to some 11,000 homes and clean-up efforts started as residents surveyed the damage.
"Everything I have is destroyed," said Victoria Salceanu in the eastern village of Slobozia Conachi.
