A state of emergency has been imposed in Russian-controlled parts of Ukraine's Kherson region following the destruction of the Nova Kakhovka dam and the flooding of large area, Russia's TASS state news agency reported on Wednesday.

The agency, citing emergency services, said about 2,700 houses were flooded after the destruction of the dam on Tuesday and almost 1,300 people had been evacuated. At least seven people were missing, Moscow-backed officials said.

The destruction of the Moscow-controlled Nova Kakhvovka dam on the Dnipro River flooded a large part of the frontline in the Kherson region. Ukraine and Russia have blamed each other for the dam collapse.

About 42,000 people were at risk from flooding in Russian and Ukrainian controlled areas along the Dnipro River, said Ukrainian officials, as the United Nations aid chief warned of "grave and far-reaching consequences".

TASS cited Nova Kakhvovka mayor Vladimir Leontiev as seven people were known to be missing. More than 900 people were evacuated on Tuesday from the Russian-controlled city of some 45,000 people on the left bank of the Dnipro River.

Ukrainian officials said that some 80 communities in the overall Kherson region were at risk of flooding.

The governor of the Kherson region, Oleksandr Prokudin, said on Wednesday that 1,582 houses had been flooded on the right bank of the river and some 1,457 people had been evacuated overnight.

Earlier, Prokudin said that one civilian person was killed and one injured as a result of Russia's shelling of the region and the city of Kherson itself.

The Kremlin on Tuesday accused Ukraine of sabotaging the dam to cut off a key source of water for Crimea and distract attention from a "faltering" counter-offensive against Russian forces.

Ukraine said Russia committed a deliberate war crime in blowing up the Soviet-era Nova Kakhovka dam, which powered a hydroelectric station.