Russia’s attack overnight on Tuesday hit the Kakhovka hydroelectric power station, causing massive flooding in the nearby areas, Ukraine’s military said.

"Russian occupation forces blew up the Kakhovka hydroelectric power station. The scale of the destruction, the speed and volume of water, and the probable areas of inundation are currently being determined," Ukrainian Armed Forces’ operational command South, where the dam is located, said in a statement.

Police and emergency service units have been alerted to warn and evacuate civilians from potential flood zones on the right bank of the Dnipro River, Ukraine’s interior ministry said.

Those include the villages of Mykolaivka, Olhivka, Lvove, Tyahynka, Ponyativka, Ivanivka, Tokarivka, Prydniprovske, Sadove, and the microdistrict of Korabel in the city of Kherson.

The interior ministry recommended that people in the areas at risk of flooding switch off all electrical appliances, take documents and basic necessities, and follow the instructions of rescuers and police.

"Use information only from official Ukrainian sources. Trust the police, emergency services, and our defenders," the statement said.

Oleksandr Prokudin, the head of the Kherson regional state administration, posted a video on Telegram urging the citizens in the areas affected to prepare for evacuation.

He said the water "will reach a critical level in five hours", pleading those who remain on the Russian-occupied left bank of the Dnipro River to make every effort to save their lives.

Kyiv warned of a possible diversion on the Nova Kakhovka dam as far back as last autumn, when the Ukrainian forces were advancing towards Kherson.

In October 2022, Ukraine’s president Volodymyr Zelenskyy told EU leaders Russians had been mining the dam and units at the Kakhovka hydroelectric power station, having already "prepared everything" for this terrorist attack.

The blow-up will likely disrupt water supply to Russia-annexed Crimea and lead to "a large number of victims", Ukraine’s national defence and security council secretary Oleksii Danilov said.