Fears over the safety risks for the nuclear plant, Europe's largest, have been constant throughout Russia's invasion, but increased in early June after the destruction of the Kakhovka dam, the source of cooling water for its reactors.

The mutual accusations were made around the same time late on Tuesday.

Kyiv's military warned of the "possible preparation of a provocation on the territory of the Zaporizhzhia power plant in the near future".

It claimed that "external objects similar to explosive devices were placed on the outer roof of the third and fourth reactors" at the site.

"Their detonation should not damage power units, but may create a picture of shelling from the Ukrainian side," it said, alleging that Moscow would "misinform on this".

In Moscow, an advisor to Russia's Rosatom nuclear agency, Renat Karchaa, accused Kyiv of planning an attack on the plant.

"Today, we got information that I am authorised to announce... On July 5, literally at night, in the dark, the Ukrainian army will try to attack the Zaporizhzhia nuclear power plant," Karchaa told Russian state television.

He claimed that Ukraine planned to use "high-precision, long-range weapons" as well as drones.

Russia and Ukraine have regularly accused each other of putting the plant's safety at risk since the outbreak of the war in February 2022.