At least 100 Russians asked for help from President Vladimir Putin on Monday in a city struck by the worst flooding ever recorded, chanting "shame on you" at local officials who they said had done too little to help their plight.

Russia declared an emergency in the Orenburg region near Kazakhstan after the Ural River, Europe's third longest river, swelled several meters in hours on Friday, and burst through a dam embankment in the city of Orsk.

Swaths of Orsk, a city of 230,000 about 1,800 kilometers east of Moscow, have been left submerged.