Intense flooding in the Black Sea region of southern Russia killed 103 people after torrential rains dropped nearly 30 centimetres of water, forcing many to scramble out of their beds for refuge in trees and on roofs.

Many people were asleep when the flooding hit overnight in the Krasnodar region and the water rushed into the area around the hard-hit town of Krimsk with such speed and volume that some people thought local officials had opened a nearby water reservoir.

Muddy water coursed through streets and homes, in some cases high enough to flow over the hoods of cars and even as high as rooftops, according to witnesses.

People waded through waist-high water or maneouvred the streets in boats.

About five-thousand residences were flooded, the Krasnodar governor was quoted as telling the Interfax news agency.

More than one thousand five hundred Emergency Ministry officials were working to aid flood victims and clean up the damage, state TV said.

Five people were electrocuted in the Black Sea coastal city of Gelendzhik after a transformer fell into the water, state news agency RIA Novosti said.