Updated 7:15pm

One person has drowned in Poland and an Austrian fireman has died responding to floods, authorities said Sunday, as Storm Boris lashed central and eastern Europe with torrential rains.

Since Thursday, swathes of Austria, the Czech Republic, Hungary, Romania and Slovakia have been hit by high winds and unusually fierce rains. 

The rains have flooded streets and submerged entire neighbourhoods in some places, while shutting down public transport and electricity in others.

Romanians waded through armpit-high water to safety, Poles sought shelter in schools and Czechs hurriedly put up sand dykes in an effort to keep the water at bay.

Sunday's deaths bring the overall toll from the storm to eight, with thousands evacuated across the continent.

In Romania, two bodies were found on Sunday, after four people were reported killed earlier and one person was declared missing.

Four people were reported missing in the Czech Republic.

"The water came into the house, it destroyed the walls, everything," Sofia Basalic, 60, a resident of Romania's village of Pechea, in the hard-hit region of Galati, told AFP.

"It took the chickens, the rabbits, everything. It took the oven, the washing machine, the refrigerator. I have nothing left," she said.

'Worst hours of their lives'

Writing on X, formerly Twitter,  EU Commission chief Ursula von der Leyen expressed "Heartfelt solidarity with all affected by the devastating floods in Austria, Czech Republic, Hungary, Poland, Romania and Slovakia", adding the EU was ready to offer support.

And on Sunday morning, Polish Prime Minister Donald Tusk confirmed the country's first reported death by drowning in the Klodzko region on the Polish-Czech border in the southwest of the country, which has been hit hardest by the floods.

Around 1,600 people have been evacuated in Klodzko and Polish authorities have called in the army to support firefighters.

Separately, a fireman in northeastern Austria died in floods in the Lower Austria region, which has been classified as a natural disaster zone, regional governor Johanna Mikl-Leitner told reporters Sunday.

"For many residents, the upcoming hours will be the worst of their lives," she said.

Emergency services had made nearly 5,000 interventions overnight in the state of Lower Austria, where flooding had trapped many residents in their homes.

A highway from western Austria to Vienna was shut just outside the capital and four of Vienna's five metro lines had been shut in the city, where the Wien river was threatening to overflow its banks, according to local news reports. 

In Poland, authorities shut the Golkowice border crossing with the Czech Republic after a river flooded its banks on Saturday, as well as closing several roads and halting trains on the line linking the towns of Prudnik and Nysa. 

Tusk said that Ukraine, which is fending off a Russian invasion in its third year, has offered to send some 100 rescuers specially equipped to deal with floods to help as an expression of solidarity with Poland, which has steadfastly backed Kyiv during the war.

"It's very touching", Tusk said of the offer.

In the Czech Republic, a dam in the south of the country burst its banks, flooding towns and villages downstream.

In the village of Velke Hostice, residents put up a wall of sandbags 500 metres long in an effort to hold back the rising waters of the River Opava.

"If we don't stop the wave, it will flood the lower part of the village," local hunter Jaroslav Lexa told AFP.

'Catastrophe of epic proportions' 

Romanian President Klaus Iohannis said, "We are again facing the effects of climate change, which are increasingly present on the European continent, with dramatic consequences". 

"We must continue to strengthen our capacity to anticipate extreme weather events."  

In Romania, four bodies were discovered in the worst affected region, Galati in the southeast, where 5,000 homes were damaged.  

Hundreds of people have been rescued across 19 parts of the country, rescue services said, releasing a video of flooded homes in a village by the Danube river. 

"This is a catastrophe of epic proportions," said Emil Dragomir, mayor of Slobozia Conachi village in Galati, where he said 700 homes had been flooded. 

Prime Minister Marcel Ciolacu was expected to visit the area later, while President Iohannis sent his "condolences to grieving families". 

Around 100,000 firefighters have been mobilised in the Czech Republic, where nearly 2,900 incidents were recorded on Friday, most of them due to fallen trees and floods. 

Almost 50,000 homes were without electricity on Saturday, Czech power company CEZ said, and a hospital in the southeastern city of Brno was evacuated on Saturday morning. 

"The ground is now saturated so all the rainwater is going to stay on the surface," Environment Minister Petr Hladik said on X, formerly Twitter. 

Residents are being offered free bags of sand to shore up their homes. 

'Peak is yet to come'

Neighbouring Slovakia has declared a state of emergency in the capital, Bratislava. 

Meanwhile in Poland, the government warned the situation would be the most difficult in the southwest going into Saturday afternoon and evening. 

Authorities have shut the Golkowice border crossing with the Czech Republic after a river flooded its banks, closed several roads and halted trains on the line linking Prudnik to Nysa. 

Austria registered winds of 146 kilometres (91 miles) an hour in the south.

Firefighters have intervened around 150 times in the capital Vienna since Friday to clear roads blocked by storm debris and pump water from cellars, local media reported. 

Four thousand homes in the Styrie region are without power and the "peak is yet to come", Chancellor Karl Nehammer warned. 

In mountainous areas of the west, snow halted traffic and rescue services were searching for a man reported missing after an avalanche. 

Some areas of the Tyrol were blanketed by up to a metre (three feet) of snow -- an exceptional situation for mid-September, which saw temperatures of up to 30 degrees Celsius (86 degrees Fahrenheit) last week.