Tens of thousands of people across south-eastern Europe are braced to battle more floodwaters as rivers continue to rise in the region.
Residents in many areas are using boats to cross flooded streets
A state of emergency has been declared in 10 regions of Serbia. Romania and Bulgaria have also been severely hit.
The Danube has risen to its highest level since 1895 in Romania. Four other rivers have also reached danger levels.
Floods in the Balkans last year left dozens of people dead and farmland and infrastructure damaged or destroyed.
In the affected countries, army and civil defence teams have been building dams and walls of sandbags to barricade the flood waters.
But as the flooding continues into a second week, there are concerns that these will become soaked through and weakened.
It is also feared that if the rivers continue to rise, they will overflow the defences anyway.
Air raid sirens have been sounded in some Serbian towns to warn people to leave their homes.
Meanwhile large swathes of farmland and low-lying villages in Bulgaria and Romania have been swamped by the overflowing Danube, which forms the border between the two countries.
In recent developments:
- Hundreds of people were taken to safety in Smederevo, 40km (24 miles) east of Belgrade, Serbia, as the waters of the Danube flooded the town. Hundreds of houses in the area are under water
- A tent city with space for 1,200 has been erected near Vidin, Bulgaria, in case residents need to flee their homes
- In the Bulgarian port town of Lom, soldiers helped boost civil defence teams, but water levels remained at record levels.
- Some residents displaced by last year's floods in Romania's western county of Timis, the worst-hit area of the country, were reported to have had their new homes flooded
In Romania, authorities have begun the controlled flooding of up to 90,000 hectares (350 sq miles) of farmland to try to reduce the flow and the danger to communities downstream.
The effort were helped by the collapse of a dam in south-western Romania which flooded farmland and let some of the pressure off.
"The water flow has fallen by 200 cubic metres per second. This is a success," Beatrice Popescu, of the environment ministry, told Reuters news agency.
Citizens and police are trying to build defences against the Danube as well as the Sava, Tisa and Tamis rivers.
Parts of Serbia's capital Belgrade are under water
In the Serbian capital Belgrade some streets have been under water for several days, forcing evacuations.
The chief of the city's flood defence team urged women to stop walking over the sandbags to avoid making holes in them with their high-heeled shoes, the AFP news agency reported.
The Danube is now flowing at nearly 16,000 cubic metres a second, more than twice the normal volume in April.
It is still rising and is expected to peak in most places on Tuesday.
"We are all mobilised and what is left now is for us to trust in God that all will end well," Serbian Agriculture Minister Ivana Dulic Markovic said.
"We must not relive the nightmare of last year," Romanian Interior Minister Vasile Blaga said.
"We must act quickly to prevent the loss of human lives."