A rapid thaw caused a real chaos on the River Danube in the Serbian capital Belgrade, where ice damaged boats, pontoons and floating restaurants.
The thick ice covered one of Europe’s busiest waterways during the recent freeze, but began to break up on Sunday as temperatures rose.
In Belgrade, boats crashed into each other but there were no immediate reports of casualties.
One boat owner said the ice had moved so fast, boats could not be saved.
“The damage will be hundreds of thousands of Euros for sure,” Dragan Jovanovic was quoted as saying by Reuters news agency.
Another boat owner, Mihailo Svilaric, told Reuters only a “handful” of boats remained intact out of about 100 moored in the Serbian capital’s Kapetanija marina.
Debris was scattered among the breaking ice for hundreds of metres along the river, and several floating restaurants, barges and boats were beached on river banks after the ice snapped anchor lines.
Local media reported that Belgrade emergency services said there was no ice risk to bridges and other infrastructure in the city, and there was no threat of flooding.
The Danube flows 2,860km (1,777 miles) through nine countries and is vital for transport, power and industry.
It has been almost entirely frozen from Austria to the Black Sea, in Romania, the Associated Press news agency reports.
Ice more than 30cm (11in) thick in places broke up over the weekend as temperatures rose.
Belgrade river officials advised boat owners to constantly monitor their property but not to try to recover it from the water as of Monday morning.
Belgrade resident Miroslav Jagas told AP he believed that complacency had aggravated the problems caused by the freezing weather.
“We have not seen weather like this in a long time,” he said.
“People were relaxed, the boats stayed there, the icebreakers did not remove the ice on time.”
At least 20 people have died from the cold in Serbia in recent weeks and economists say damage from the cold snap may cost Serbia as much as 500 million Euros ($660 million).
Some 3,300 people remain stranded by snow and ice in rural areas, where they can only be reached by helicopter.