PARIS -- Rivers in Europe have burst their banks from Paris to the southern German state of Bavaria, killing six people, trapping thousands more in homes or cars and forcing everything from subway lines to castles to the Louvre to shut down.
French authorities were especially concerned about the rising waters of the Seine River, which winds through Paris and was expected to peak Friday.
Paris police upgraded their flood warning to "orange" -- the second-highest level -- for areas in the French capital near the Seine, which has already overflowed its banks in many places. The warning means floods could have "a significant impact" on buildings and people.
The Louvre Museum in Paris says it will be closed Friday to remove artworks from rooms threatened by rising waters from the Seine and preventatively shift them upstairs. Its most famous painting, Leonardo da Vinci's "Mona Lisa," is staying put on an upper floor, however.
The Orsay museum, on the left bank of the Seine, will also be closed Friday to prepare for potential flooding.
Tourist boat cruises in Paris have been cancelled and roads in and around the capital are under water. A suburban train line that runs alongside the Seine in central Paris, serving popular tourist sites like the Eiffel Tower, the Invalides plaza and the Orsay museum, was shut down but other subway lines were running normally.
Days of heavy rains have caused exceptional delays to the French Open tennis tournament and may force it into a third week.
France's meteorological service said Thursday that severe flood watches remained in effect in one Paris-area region: Seine-et-Marne. Nine more regions in central France, including Paris, were facing flood warnings as well.
Fara Pelarek, 44-year-old Australian tourist visiting Paris, said she was "very surprised" to see the Seine so high.
"I remember walking down below (before) and it was very easy," she said. "In a way, it's kind of nature taking over."
For the second day, emergency workers evacuated residents in Nemours, 80 kilometres (50 miles) south of Paris, the hardest-hit site in France.
Areas along the Loing River, a tributary of the Seine, were facing water levels unseen since 1910, when a massive flood swamped the French capital. The situation improved somewhat late Thursday, yet about 21,000 homes were still without electricity.
In the Loire valley in central France, the renowned castles of Chambord and Azay-le-Rideau were closed because of floods in their parks.
The rains that have fallen across Western Europe this week have already killed six people, including an 86-year-old woman who died in her flooded home in Souppes-sur-Loing, southeast of Paris. In southern Germany, five people were killed as floods swept through the towns of Simbach am Inn and Triftern near the Austrian border.
French President Francois Hollande said a "natural disaster" will be formally declared next week for areas most affected by the flooding -- and a separate fund will help villages and small towns deal with the damages.
In Berlin, German Chancellor Angela Merkel, meanwhile, promised continued help for flooded areas, telling reporters Thursday that she "mourns for those for whom the help has come too late, who lost their lives."
The floodwaters in Bavaria receded somewhat and disaster relief crews were helping to clear the wreckage, but there were warnings of more storms.
Belgium endured a fourth day of heavy rain, with flooding reported in several areas. After widespread flooding hit northern Antwerp and the west of Flanders early in the week, waters kept rising in eastern areas around Limburg and Liege. Several neighbourhoods have had to be evacuated as cellars flooded and streets were submerged.
A major train line linking Limburg to the Belgian capital of Brussels was temporarily suspended Thursday.
Geir Moulson, David Rising in Berlin and Raf Casert in Brussels contributed to this report
