The Ukrainian state-run energy company Ukrenergo said on Wednesday that the Chernobyl nuclear power plant in northern Ukraine has been disconnected from the power grid.
"The nuclear power plant in Chernobyl was fully disconnected from the power grid. The nuclear station has no power supply," Ukrenergo said in a statement on Telegram.
Military actions in the area are in progress so there is no possibility to restore the power lines, the statement said.
Ukrainian Foreign Minister Dmytro Kuleba on Twitter called on the international community to urgently demand Russia to cease fire and allow repair units to restore the power supply to the nuclear power plant.
"Reserve diesel generators have a 48-hour capacity to power the Chernobyl NPP. After that, cooling systems of the storage facility for spent nuclear fuel will stop, making radiation leaks imminent," Kuleba tweeted.
On Tuesday, the Vienna-based International Atomic Energy Agency (IAEA) said that remote data transmission from the safeguards control systems installed at the Chernobyl plant has been lost.
However, the United Nations nuclear watchdog denied any critical safety risk after receiving the Ukrainian report about the loss of power at the Chernobyl nuclear power plant on Wednesday.
"Heat load of spent fuel storage pool and volume of cooling water at Chernobyl Nuclear Power Plant sufficient for effective heat removal without need for electrical supply," the IAEA said in a statement posted on Twitter.
The Chernobyl nuclear plant, some 110 kilometers north of Kiev, witnessed one of the worst nuclear accidents in human history on April 26, 1986.
On Feb. 24, advisor to the Head of the President's Office of Ukraine Mykhailo Podoliak said Russian forces have seized the Chernobyl nuclear power plant.