Thousands of emergency workers, troops and volunteers in Germany battled Sunday against central Europe's worst floods in over a decade, while the swelling Danube put Budapest on high alert.
Rising flood waters in Germany have forced mass evacuations in what one lawmaker termed a "national catastrophe."
As Hungary braced for a deluge in its capital, bolstering sandbag barriers as the Danube is expected to reach historic levels, German rescuers focused on the eastern city of Magdeburg.
Vast areas around the city were covered in a sea of brown water, sparked by recent torrential rains which have washed down the Elbe river system from the Czech Republic.
The water level in Magdeburg reached 7.45 metres (24 feet) in the morning, up from the usual level of around two metres and worse than massive floods that struck the region in 2002, local authorities said.
Despite frantic efforts to secure it, a dam broke on Sunday south of the city at the point where the Elbe meets the Saale tributary, the local crisis command said, urging the remaining 150 residents in the region to quickly seek high ground.
Almost 3,000 residents were evacuated from Magdeburg's Rothensee district, where hundreds of army troops struggled to reinforce a dyke protecting a crucial electricity facility.
President Joachim Gauck on Sunday went on a tour of the flood-hit states of Saxony and Saxony-Anhalt, where in vast areas only roofs and tree tops stick out of the water and the only access is by boat or helicopter.
"One cannot imagine how much remains to be dealt with," said Gauck in view of the massive clean-up, after joining a church service in the city of Halle.
So far the floods on the Elbe and Danube river systems have killed at least 18 people, including 10 in the Czech Republic.
Ironically, the sun was shining brightly above Germany's flood zone, forcing the thousands packing sandbags and helping evacuees to ask for supplies of sun block and insect repellent against mosquitos.
More townships were evacuated around the Elbe town of Barby. Some of the 8,000 residents of the nearby town of Aken were taken to safety on military armoured personnel carriers and ambulances.
Chancellor Angela Merkel's government was planning a crisis meeting with state premiers to assess how the cost of the disaster will be shared, the Leipziger Volkszeitung daily reported in its Monday edition.
"We're dealing with a national catastrophe," Gerda Hasselfeldt, lawmaker for the conservative Christian Social Union, who chairs a group of states in the Bundestag, told the newspaper.
There was growing anger about gawkers hindering the emergency response, which also extended in villages and towns downriver along the Elbe and its tributaries into Lower Saxony state.
"Disaster tourism is a serious problem," said Hans-Peter Kroeger, head of the associations of fire brigades, according to national news agency DPA. "Sightseers with their cars block roads and depots, get in the way of emergency responders, threaten the safety of dykes and endanger themselves."
The situation in the Czech Republic was getting back to normal, after the crest of the flood passed through, although flood defences stayed in place after forecasts of storms and heavy rain.
"The danger lasts even in places hit by the flood" as the soil is still soaked, Prime Minister Petr Necas said Saturday after a crisis committee meeting.
-- Hungary flood peak nears 'heart of the country' --
The rains have also severely swollen the Danube, hitting especially Germany's Bavarian city of Passau, where the mighty waterway meets two other rivers, leaving thousands of homes covered in mud and debris last week and some villages abandoned and cut off.
The high river sparked emergency responses as it runs through Austria and Slovakia into Hungary on its way to the Black Sea, but so far the region has dodged a major disaster.
Hungary's flood defences held firm Sunday morning as the flood peak moved through the northwest of the country toward Budapest.
No casualties or serious injuries had been reported yet in Hungary although authorities said around 1,000 people had been evacuated. So far, around six million sandbags have been used in barriers.
The river was forecast to peak at 8.95 metres in Budapest late Sunday. By morning the water level had already climbed to 8.83 metres, exceeding the previous historic high of 8.60 recorded in 2006.
Authorities in the capital said the flood barriers now in place are high enough to protect even the most threatened parts of the city.
"The flood peak is approaching the heart of the country," said Prime Minister Viktor Orban. "Two very important days are ahead of us, as the capital is the most densely populated part of the country."