Footage has emerged of crowds of Ukrainian civilians blocking access to a nuclear plant as Russian troops move in.
The city of Enerhodar, located on the banks of the Dnieper River, in the southeast of Ukraine, is home to the Zaporizhzhia nuclear power plant, the largest nuclear plant in Europe.
In videos widely circulated on social media, a crowd of hundreds of people can be seen blocking the road to the plant, while heaps of tyres and sandbags can be seen across the road to stop any vehicle access.
Lorries can also been seen parked across the road.
Dmytro Orlov, mayor of Enerhodar, said on his Facebook page that the nuclear plant "is under reliable protection", and added that "workers and residents of Enerhodar are under Ukrainian flags".
He added: "Nobody is going to surrender the city. People are determined."
He had earlier warned that Russian forces were "approaching" and called on residents to head to the city entrance to prevent occupants from advancing.
The Ministry of Defence said the latest intelligence suggested Russian forces have moved into the centre of Kherson in south Ukraine, which is located around 200km from Enerhodar.
Russian air strikes have so far targeted built-up areas in Kyiv, Kharkiv, Mariupol and Chernihiv.
The Vienna-based International Atomic Energy Agency (IAEA), the United Nations’ nuclear watchdog, said it had received a letter from Russia saying its military had taken control around Ukraine’s largest nuclear power plant.
But according to the letter, personnel at the plant continued their “work on providing nuclear safety and monitoring radiation".
It added that the “radiation levels remain normal”.
Mayor Orlov had previously disputed a claim that the Russians had already captured the plant.
Last week, Russia seized control of the decommissioned Chernobyl nuclear power plant, scene of the world’s worst nuclear disaster in 1986.
The IAEA says that it has received a request from Ukraine to “provide immediate assistance in coordinating activities in relation to the safety” of Chernobyl and other sites.