Europe's largest nuclear power plant has been seized by Russian forces as the conflict in Ukraine enters its ninth day.
The Zaporizhzhia plant in southeastern Ukraine came under attack overnight as Russian President Vladimir Putin rained down "nuclear terror".
A spokesperson for the nuclear power plant, Andrii Tuz, told CNN that the facility was attacked "from air, from tanks, from rockets, from many, many armour" and that a nuclear accident could happen "at any moment".
“I have no idea how far Putin will go. Nobody believed that they could start shooting at a nuclear power plant. We need to stop the war now! And not wait for the onset of a nuclear catastrophe," he said.
Following the fighting, a fire broke out at the facility, prompting fears that an explosion could lead to a catastrophe “10 times worse than Chernobyl”.
Ukraine President Volodymyr Zelensky said: "For the first time in our history, the history of mankind, the terrorist state has resorted to nuclear terror.
"Russian protagonists have threatened to cover the world with nuclear ashes, now it is not a threat, now it is a reality. We must stop the Russian military immediately."
The blaze was extinguished on Friday morning and the International Atomic Energy Agency said “essential” equipment at the plant was not damaged.
The agency has nonetheless put its Incident and Emergency Centre "in full 24/7 response mode due to the serious situation at Zaporizhzhia".
Russian troops have since taken control of the plant, Ukrainian authorities said.
"Operational personnel are monitoring the condition of power units," a local authority said on social media as quoted by Reuters.
The incident has received widespread condemnation, with the West denouncing the "reckless" attack.
Foreign Affairs Minister Simon Coveney said the incident poses a "grave threat" to all of Europe.
He said on Twitter: "Russia’s attack on the #Zaporizhzhia nuclear power station is utterly reckless.
"Russia’s military activity in the area must cease immediately. This is a grave threat to the European continent. Our full support to the @iaea and DG @rafaelmgrossi in their essential work."
Rafael MarianoGrossi, the Director General of the International Atomic Energy Agency, said: "I'm deeply concerned with situation at #Zaporizhzhia Nuclear Power Plant.
"Spoke with #Ukraine PM Denys Shmygal; @IAEAorg's monitoring and in close contact with #Ukraine's nuclear regulator and operator. I appeal to parties to refrain from actions that can put NPPs in danger."
US President Joe Biden spoke to President Zelenskyy and is "urging Russia to cease its military activities in the area and allow firefighters and emergency responders to access the site", the White House said.
UK Prime Minister also spoke with the Ukrainian President about "the gravely concerning situation at Zaporizhzhia nuclear power station".
"Russia must immediately cease its attack on the power station and allow unfettered access for emergency services to the plant," he said.
