Four people died in Romania in floods after heavy rains that affected Central and Eastern Europe, emergency services announced.
The highest flood alert was declared on Saturday in 38 locations throughout the Czech Republic.
In the capital city of Prague, city flood barriers were erected, embankments were closed, and so was the zoo, Czech authorities announced.
Evacuations have also begun in Poland as rivers rise to dangerous levels.
The bodies of four victims in Romania were found in the Galac region in the south of the country during a search and rescue operation, the emergency services of the AFP agency confirmed.
"Dozens of people were rescued from their homes in 19 regions of the country," they add.
- The summer of 2024 was the hottest on record
- May floods 2014: The days when "the water merged with the gray sky" and Obrenovac became a "swamp"
- Did 'cloud seeding' cause floods in Dubai?
Polish Minister of the Interior Tomaš Šemonjak said that residents of small towns near the border with the Czech Republic - Morov and Gluholazi - are facing a dangerous situation.
In Gluholazi, the water level of the river exceeded the safe level by two meters, and the residents of the surrounding streets were evacuated.
"The situation is very bad. The state of the river and the forecast are still bad," Šemonjak said.
"We have a difficult situation on four rivers, we are threatened with potential evacuation and damage in several cities," he added.
Cyclone Boris has brought strong winds and heavy rains to parts of Poland, Austria, the Czech Republic, Hungary, Romania and Slovakia since Thursday.
* Češka
The Czech capital, Prague, does not want to take any chances after the floods that devastated the city two decades ago.
Images of flooded metro stations in 2002, evacuation of residents in rubber boats, and drowning elephants in the Prague Zoo are etched in local memory.
A little before ten o'clock on Friday, a heavy steel rampart, one meter thick, closed the so-called Devil's Canal or Čertovka, which cuts through the historic district of Mala Strana in Prague, returning to the Vltava River.
Čertovka is part of a national flood defense network that officials say cost more than a billion euros to prevent catastrophic damage in 1997 and 2002.
In Prague, they hope to avoid the worst floods.
This weekend, attention is focused on the central and eastern parts of the country, especially on North Moravia, where 1997 people lost their lives in 50.
About 400 millimeters of rain could fall on the Jesenjiki mountains in the next three days, and this water will then flow down the Odra river and further towards Poland, passing a number of towns and villages on its way.
BBC is in Serbian from now on and on YouTube, follow us HERE.
* Poljska
After attending a meeting of emergency services in southwestern Poland, the Prime Minister of this country, Donald Tusk, tried to assure the public that the forecasts "are not overly alarming".
Poland's territorial defenses were on alert, he said, and in one of the four southern provinces, Lesser Poland, an estimated two million sandbags were stacked, while another million were available in Lower Silesia, the province surrounding the city of Wroclaw.
"If something can be expected, and we want to be prepared for it, it is of course localized floods or so-called flash floods," he added.
Thousands of residents in Wroclaw had to walk up the stairs to their apartments because the elevators were not working due to fear of flooding, local media reported.
The Polish Institute of Meteorology and Water Management later extended the highest alert level from the four southern provinces to the mouth of the Oder River in the Baltic Sea, in Szczecin.
* Austrija
Austria has recorded the warmest August since it has been measured, according to data from the federal institute Geosphere Austria.
There are now warnings of 10-20 centimeters of rain in many regions in a few days.
In some places, more than 20 centimeters is possible, especially in the mountains of Upper and Lower Austria and in northern Upper Styria.
From the Austrian Storm Warning Center UWZ they state that in some areas the previous records for the whole of September will be "surpassed in just a few days".
Manuel Kelemen, Puls24 television forecaster, says that from a meteorological point of view, "what we are experiencing is extraordinary, if not unprecedented".
The Austrian railway network OBB has advised all passengers to postpone non-urgent journeys.
Part of the Tauern railway line between Bad Hofgastein and Beckstein in the province of Salzburg is closed due to heavy snowfall.
Floods and landslides are possible, and stormy winds are expected in the capital city of Vienna.
The humanitarian organization Caritas appealed for volunteers to help in the affected areas.
Continuous heavy rain is also expected across the border, in the German province of Bavaria.
It is a regional, not a national emergency, where a large area of central Europe is affected.
A reminder of national priorities came earlier this week when Czech officials said they were forced to refuse a German request to stop emptying man-made lakes in the Vltava, which flows into the Elbe river and on into Germany, following the collapse of a bridge in Dresden.
Those man-made lakes, a series of nine dams known as the Vltava Cascade, will have to remain half-empty to handle the volumes of water that are being forecast this weekend.
Follow us on Facebook, Twitter, Instagram, YouTube i Viber. If you have a topic suggestion for us, please contact bbcnasrpskom@bbc.co.uk
Bonus video:
