Flooded River Breaches Dam in Germany, 23,000 Asked to Evacuate [VIDEO]

Thousands of people were advised to evacuate their homes in eastern Germany after a dam containing the swollen Elbe River burst, causing more flooding in a region pummeled by historic rains.

Monday approximately 23,000 people were asked to evacuate the regional capital of Magdeburg after water levels rose to a record 7.48 meters (24.5 feet), about 5 meters (16 feet) above normal levels, according to Al Jazeera news.

"We helped yesterday to carry sandbags to secure the town. The mood is very depressed and frightened because many people have to leave their homes," Magdeburg resident Liane Nagen told Reuters.

Despite attempts to stabilize it, the dam south of Magdeburg at the joint of the Elbe and Saale Rivers burst Sunday, flooding many streets and buildings and forcing the area's electricity to shut off, The Guardian reported.

A week of torrential rain and heavy flooding has been attributed to at least 21 deaths in Germany, Austria, Slovakia, Poland and the Czech Republic, as well as numerous evacuations, including one at the Prague Zoo, where about 1,000 animals had to be transported to higher ground.

A letter threatening to blow up dams elsewhere along the Elbe River has also been widely reported.

Holger Stahlknecht, Interior Minister for the state of Saxony-Anhalt, where Magdeburg is located, told Reuters that surveillance would be stepped up in response to the threat, which reportedly came from a previously unheard-of group calling itself the Germanophobic Flood Brigade.

The bomb threat is being "taken very seriously" and investigated by authorities, Stahlknecht said.

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