Russian strikes have damaged nuclear substations in Ukraine, leading the International Atomic Energy Agency (IAEA) to issue a "critical" warning.
Power to three nuclear power plants has been affected after Russian strikes on Thursday.
The IAEA said teams at South Ukraine Nuclear Power Plant and Khmelnitsky Nuclear Power Plant reported the plants had lost access to one of their off-site power lines.
In a statement, the IAEA said: "The IAEA has been informed of military activity in Ukraine early this morning that has led to damage to substations critical to nuclear safety and security in Ukraine."
IAEA director General Grossi said: "The dangers to nuclear safety continue to be very real and ever-present.
"I once again call for maximum military restraint in the vicinity of nuclear facilities and full respect of the seven indispensable pillars for nuclear safety and security."
Zelensky: 'This Is Outright Terror'
Separately, Volodymyr Zelensky, the Ukrainian president, said Russia has launched an attack on the Slovyansk Thermal Power Plant on Thursday.
"This is outright terror. Normal people don’t wage war like this, and the world must respond appropriately to such Russian warfare," he said in a post on X on Thursday evening.
Russia Fires 'Secret Missile' at Ukraine
Russia has struck Ukraine with a cruise missile, the secret development of which led to U.S. President Donald Trump ending a nuclear arms control pact with Moscow in 2019, Kiev has claimed.
Andrii Sybiha, Ukraine's foreign minister, said Russia had begun using the ground-launched 9M729 missile.
An unnamed Ukrainian official told Reuters Russia had fired the missile at Ukraine 23 times since August
"Russia's use of the INF-banned 9M729 against Ukraine in the past months demonstrates (President Vladimir) Putin's disrespect to the United States and President Trump's diplomatic efforts to end Russia's war against Ukraine," Sybiha said in a written statement.
There was no comment from Russia.
