Several regions in Germany were hit by extreme rainfall on Saturday.
In the East German state of Saxony, more than 100 liters of precipitation per square meter fell within 24 hours, resulting in flooding.
More to the south, the Oberbayern region of Bavaria has been affected.
The situation there is dire, according to the emergency services.
Two people have died in that area, but it is unclear whether their deaths have anything to do with the flooding.
In Saxony there is flooding in Saxon Switzerland, a popular hilly tourist region near Dresden.
The local authorities announced on Saturday evening that several places are no longer accessible: Neustadt, Sebnitz, Bad Schandau, Reinhardtsdorf-Schoena and Gohrisch have been hit especially hard.
The population is advised to avoid cellars, underground garages and the metro.
The railway line between Bad Schandau and the Czech De Tsjechischein is closed.
"The situation is tense, but manageable," said the crisis center of the state's interior ministry.
Alert level 4 has been exceeded on the river Polenz near Neustadt, the state flood control center says.
The rivers Kirnitzsch, Sebnitz and Lachsbach are experiencing an "extreme rise in water level".
"Severe flooding is to be expected," a government agency said on Saturday evening.
Since Saturday afternoon, aid workers have had to turn out more than 250 times.
#BadSchandau: Torrential rainfall has led to flash flooding in the Saxonian towns of Bad Schandau, Sebnitz and Neustadt in Sachsen.
Train service between Dresden and Prague has been suspended as emergency services deal with flooded homes and streets.
AuthorBreakingIENMoment of places19: 52 - July 17, 2021
Oberbayern has also been hit hard.
There have been evacuated houses, landslides, flooded streets and submerged basements since Saturday evening.
The fire brigade is busy.
The situation is "dramatic" say the emergency services of the region around Traunstein.
Berchtesgaden and Bischofswiesen, in the far south near the border with Austria, have been particularly hard hit.
The water flows from the mountains and the water level of the Ache rises sharply.
Some houses have been evacuated.
The population is advised to leave cellars and not to go out on the streets.
Several smaller highways have been flooded or closed due to landslides.
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