Thousands of residents of Nysa, in southern Poland, formed a human chain overnight to pass each other sandbags, building a wall along a river embankment to keep the raging waters at bay.

Residents describe how a human chain in this Polish town created a sandbag wall to fight floods:::: Nysa, Poland:: Grzegorz Grochowski, Local resident:: "You can see here the remaining sandbags, overnight people were carrying the sandbags.

Experts say the most severe floods to hit Central Europe in at least two decades fit into a broader pattern of extreme weather events.

Soldiers have dropped sandbags from military helicopters to reinforce river embankments and evacuated residents as the worst flooding in years spreads across Central Europe

A massive floodwave moving across Central Europe is threatening new areas and raising concerns among residents and leaders.

Poland has declared a state of disaster in the area and set aside 1 billion zlotys ($260.38 million) for flood victims. Overnight, volunteers helped rescue workers heave sandbags to build up the broken embankment around Nysa,

Volunteers and emergency workers raced to secure river banks in the historic Polish city of Wroclaw on Tuesday, as residents elsewhere in central Europe tallied the cost of floods that have wreaked havoc and killed at least 21 people.

Border areas between the Czech Republic and Poland were hit especially hard by floods over the weekend, with Romania and Austria also affected.

The death toll from extreme weather and flooding in central and eastern Europe has risen to 22. Authorities said that there more deaths were reported in Poland and one in Austria in the wake of Storm Boris.

By Kuba Stezycki, Janis Laizans and Radovan Stoklasa WROCLAW, Poland/OSTRAVA, Czech Republic (Reuters) -Residents and emergency workers raced to secure river banks in the historic Polish city of Wroclaw on Tuesday,