Emergency Situations Minister Alexander Kurenkov on Sunday said a major flood in the city of Orsk that forced several thousand people to evacuate after a dam burst has created a "critical" situation.

He said from the city of 200,000 people, a critical situation developed in the city of Orsk., which is in southern Urals close to the border with Kazakhstan.

More than 4,500 homes have been flooded and more than 4,000 people evacuated from Orsk to temporary housing centres, Kurenkov said.

Images diffused on the Telegram social media channel showed the minister on a small boat surrounded by members of the emergency services.

Torrential rain caused the dam in the Orenburg region to burst on Friday night.

Authorities have opened a criminal case for "negligence and violation of construction safety rules" over the burst dam, which was built in 2014.

They have warned of a dangerous water level on the Ural river in the main city of Orenburg.

Reports have it that It has been classed a "federal emergency" with reinforcements sent to the region and extra funds released to deal with the urgent situation.