Russia on Monday accused Ukraine of attacking the Zaporizhzhia nuclear power station with a drone for the second day running, after Kyiv had earlier pointed the finger at Moscow.
The plant in southern Ukraine, Europe's largest nuclear facility, has been under the control of Russian forces since the first days of the military offensive in early 2022.
Both sides have regularly traded accusations of attacking the facility over the last two years, accusing each other of risking a potentially devastating nuclear disaster.
"Attempts by the Ukrainian armed forces to attack the Zaporizhzhia nuclear power plant continue," the Russians controlling the facility said on Telegram on Monday.
"Today a kamikaze drone was shot down over the plant. It fell on the roof of unit 6," they said, referring to one of the power station's reactors.
They said there was no threat to the plant's safety.
Russian forces have controlled the Zaporizhzhia nuclear plant since they seized it in March 2022.
Ukraine had earlier said Moscow was spreading "fake" information that Kyiv had fired drones at the plant on Sunday.
The head of Ukraine's centre for countering disinformation, Lieutenant Andriy Kovalenko, said Russia was intensifying a "campaign of provocation and fakes".
He said it was Russia that was attacking the facility "with drones, pretending that the threat to the plant and nuclear safety is coming from Ukraine".
'Nuclear dangers'
Russia's nuclear agency Rosatom said there was a "series of attacks" on Sunday.
It alleged that one drone had struck the site's canteen, wounding three staff members, one of them "severely".
Drones also hit a cargo port and the roof of one of the power plant's six nuclear reactors, it said.
The International Atomic Energy Agency (IAEA), which has experts at the plant, said Sunday's strikes resulted in one casualty.
"This is a major escalation of the nuclear safety and security dangers facing the Zaporizhzhia nuclear power plant.
"Such reckless attacks significantly increase the risk of a major nuclear accident and must cease immediately," Director General Rafael Grossi said on Sunday.
The IAEA said on Sunday there were no indications of "damage to critical nuclear safety or security".
Rosatom urged Grossi and Western nations to "categorically condemn" the attack.
Ukraine's Kovalenko accused Russia of "manipulating the concerns of the IAEA" and "trying to accuse Ukraine of nuclear terrorism".
A spokesman for the Ukrainian defence ministry's main directorate of intelligence, Andriy Yusov, had earlier accused Russia of endangering the power station and carrying out "simulated strikes".