The strike damaged a power line at the facility, causing the stoppage of several transformers and forcing a brief launch of emergency generators, Ukrainian nuclear operator Energoatom said on Telegram.

"Russian terrorists shelled the Zaporizhzhia nuclear power plant again" during the night, Energoatom said.

But radiation remained "at the normal background values level," it said.

"Emissions and discharges of radioactive substances into the environment do not exceed the established permissible values."

Rafael Grossi, director of the UN's International Atomic Energy Agency (IAEA), renewed his warning of "playing with fire" at the plant.

"The situation is still getting worse and we can't wait for something regrettable to happen," Grossi said at the United Nations headquarters in New York.

"I've proposed technical parameters to give the necessary protection to this installation," he told reporters after a meeting led by French President Emmanuel Macron.

Grossi said he had met in New York with Russian Foreign Minister Sergei Lavrov and was speaking later with Ukraine's top diplomat Dmytro Kuleba.

But he acknowledged the lack of progress in his recommendation of a security zone around the plant.

"Demilitarizing is an objective but for now it's about protecting the plant," Grossi said.

He said that the IAEA was seeking to enlarge its presence but that "we don't have enforcing powers," with the agency holding its influence through its reports.

Energoatom called for "more resolute actions" against Russia, saying that even "the presence of IAEA inspectors does not stop" them.

Europe's largest atomic facility was seized by Russian troops in March and shelling around it has spurred calls from Kyiv and its Western allies to de-militarize areas around nuclear plants in Ukraine.

Early in the war there was fighting around Chernobyl in the north, where an explosion in 1986 left swaths of the surrounding territory contaminated.

Russian President Vladimir Putin has warned of "catastrophic" consequences of fighting there, leading Ukraine to charge that Moscow is using the security of Zaporizhzhia as blackmail.

Russia was accused on Monday of bombing a third nuclear plant, Pivdennoukrainsk, in the southern Mykolaiv region.