Ukraine's state nuclear agency, Enerhoatom, said parts of the captured Zaporizhzhia nuclear plant were "seriously damaged" after a station containing oxygen and nitrogen and an "auxiliary building" were struck by shelling. There is now an increased risk of fire and radiation.
On Telegram, the agency said Saturday: "The Zaporizhzhia nuclear power plant is operating at risk of violating the norms of radiation and fire protection."
"There remains a risk of hydrogen leaking and radioactive particles dispersing, and the risk of fire is also high," Enerhoatom added.
Moscow and Kyiv have traded accusations about who is responsible for the attacks on the plant. The state energy company said Ukrainian power plant personnel were working to maintain safety levels but they remain under threat as Russian forces occupy the plant.
On Friday, shelling hit a high-voltage power line at the plant. Technicians disconnected a reactor as a precaution even though no radioactive leak was detected.
The International Atomic Energy Agency (IAEA) chief Rafael Grossi has called for access to the facility for weeks and has described the situation there in extremely precarious terms. Ukraine has rejected those requests out of concern that it legitimizes Russia's occupation of the plant.
Grossi said Saturday that the shelling at the plant "underlines the very real risk of a nuclear disaster that could threaten public health and the environment in Ukraine and beyond."
Ukraine said employees of Russian state atomic energy agency Rosatom left the site before shelling began while Ukrainian workers had stayed on. Ukraine added the plant continues to generate electricity.
On Twitter, the EU's top diplomat Josep Borrell "condemns" military activity around the plant. He called it "a serious and irresponsible breach of nuclear safety rules and another example of Russia’s disregard for international norms."