Ukraine's state-owned power company reported on Monday that a Russian attack caused a power outage at Zaporizhzhia nuclear power plant but announced hours later that power has been restored.

Energoatom initially said on social media that the last high-voltage transmission line had been disconnected for the seventh time since Russia started its occupation of the Ukrainian power plant.

It also said all the plant's diesel generators started operating automatically but that there is enough fuel stock left to operate them for 10 days.

It added Russia's continued occupation of the plant is constantly pushing the plant closer to being impossible to repair.

Director General of the International Atomic Energy Agency Rafael Grossi tweeted on Monday that the nuclear safety situation at the plant is extremely vulnerable. He also called for the immediate protection of the plant.

The IAEA has been urging Russia and Ukraine to agree to establish a nuclear safety and security protection zone at Zaporizhzhia, Europe's largest nuclear power plant.

The frequent shutdowns of external power supply from shelling have raised fears that an accident could occur at the plant.