The death toll in the extreme weather and flooding let loose by Storm Boris in central Europe has risen to 22, authorities said on Tuesday, after three more victims were reported in Poland and one in Austria.

High winds and unusually heavy rainfall have hit swathes of Austria, the Czech Republic, Hungary, Poland, Romania and Slovakia since last week. 

Although the weather seemed to be stabilizing in several places, the ground remained saturated and rivers were overflowing, with authorities asking people to remain cautious.  

Two big cities in Poland, Opole in the south and Wroclaw in the west, were still awaiting the flood wave and there were concerns that the dykes there could break. 

Prime Minister Donald Tusk on Tuesday announced additional government aid for those in Poland hit by the storm, bringing the total sum to 2 billion zloty ($520 million).

Polish police on Tuesday reported that three more people had died as a result of Storm Boris, raising the toll in the country to seven. 

Police chief Marek Boron announced the updated figure of seven dead at a televised crisis meeting.

At least two of the new victims were discovered in the southwestern district of Klodzko. 

"The body of an 82-year-old man was discovered in a car," district police spokeswoman Wioletta Martuszewska said.  

"A couple of hours later, mountain rescue services said the body of a man had been found near a riverbed," she added. 

There were unofficial reports of additional victims elsewhere, but police cautioned against publishing unverified information. 

"We ask everyone not to report false information about the number of flood victims in the media," the police said on X, formerly Twitter. 

'Disaster' 

A new victim was also reported on Tuesday in Austria. 

An 81-year-old woman was Austria's fifth victim of the floods, a police spokesman said.  

The fire brigade found the woman's body on Tuesday in her flooded home in Lower Austria, the worst-impacted province in the Alpine nation. 

Storm Boris has caused the deaths of seven people in Romania and three in the Czech Republic, according to the latest tallies.  

In Austria, on Tuesday, 26 communities were cut off and with the weather improving, "we are discovering the scale of the disaster," Lower Austrian governor Johanna Mikl-Leitner told reporters.

In the Czech Republic, more than 60,000 homes were still without electricity, mainly in the country's northeast, and 500 people were evacuated on Monday evening, including children.

The largest Czech retention basin, the Rozmberk pond in the country's south, has been overflowing its banks.

Experts say climate change caused by greenhouse gas emissions generated by human activities is increasing the frequency and intensity of extreme weather events, such as torrential rains and floods.

Andreas von Weissenberg of the International Federation of Red Cross and Red Crescent Societies (IFRC) said studies to determine whether climate change is linked to these events are expected in the coming months.

Von Weissenberg said local Red Cross teams were helping the rescue and evacuation efforts, including attending to people's "emotional and mental health."

He said the floods have been "branded as historic," but warned that "climate change has a way of moving the goalposts."

(Cover: The partially collapsed Carola Bridge (Carolabruecke) is pictured in the city center of Dresden, Saxony, eastern Germany, September 17, 2024. /CFP)