The level of the Ural River rose to new record highs Friday in the city of Orenburg as critical flooding forced the evacuation of tens of thousands of people in Russia and Kazakhstan, authorities said.
Fast-rising temperatures have melted snow and ice, and along with heavy rains have caused a number of major rivers that cross Russia and Kazakhstan to overflow.
In Western Siberia, the Ishim river has also risen to dangerous levels, according to authorities in the Tyumen region. Officials have predicted that the Ishim and Tobol rivers will only reach a peak level around April 23-25.
The Ural river has reached 11.29 metres (37 feet) in Orenburg, two metres above its critical level, according to city authorities. In some parts of the city only the roofs of houses can now be seen above the brown water.
A regional official, Sergey Balykin, told the RIA Novosti state news agency that the peak in Orenburg would come only on Friday or Saturday. Authorities say that more than 10,700 people out of a population of more than 400,000, have been evacuated, and that around 11,700 homes have been flooded.
Several villages have also been evacuated in the Kurgan and Tomsk regions further east.
About 100,000 people are estimated to have left their homes in Russia and Kazakhstan.
Authorities said however that conditions had improved in Orsk, which was badly hit after dam breached. Officials said water levels were falling again.
Some demonstrations, rare in Russia under the current government, have been reported by inhabitants of towns angry at the handling of the crisis.
No direct link has been made between the floods and global warming. But experts say the higher temperatures across the planet will cause the heavy rains blamed for the flooding.