Polish Prime Minister Donald Tusk on Monday announced millions of dollars in aid for those in Poland hit by Storm Boris, as the death toll in the country climbed to four following torrential rains and flooding.

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

"At the moment we have ensured a reserve of one billion zloty (US$260 million) for places and people affected by the flood," Tusk told reporters.

"From today, anyone affected by the flood... and here I mean through flooding, collapsed buildings, flooded garages, lost cars, losses linked to the flood... will be able to easily claim funds," he added.

Four people died in Poland from the storm, according to an updated toll Monday from police.

Fourteen people were reportedly killed as Storm Boris lashed central and eastern Europe with torrential rains and flooding, several more are missing and millions were evacuated from their homes. (AFP)