Ukraine's largest nuclear power plant has been hit by drone strikes in a "major escalation" that could have caused a serious accident, the UN's atomic watchdog warned.
The Zaporizhzhia plant in Russian-occupied territory was hit for the first time since November 2022, the International Atomic Energy Agency said. It is not yet clear who was responsible.
Russia said Ukrainian forces attacked the plant with drones, striking a reactor and injuring three people.
Ukraine denied responsibility, saying Russia was firing drones at the plant.
Staff with the International Atomic Energy Agency stationed at the site reported that Russian troops "engaged what appeared to be an approaching drone". IAEA staff reported explosions and rifle fire at the site throughout the day and said there was blood near a damaged vehicle.
While there was no indication of critical damage to the nuclear plant, the strikes were a "stark reminder" of the risks to the site as the war rages on, the IAEA said.
IAEA director general Rafael Grossi said attacking a nuclear power plant was "an absolute no go".
"This is a major escalation of the nuclear safety and security dangers facing the Zaporizhzhia nuclear power plant," he said.
"Such reckless attacks significantly increase the risk of a major nuclear accident and must cease immediately. No one can conceivably benefit or get any military or political advantage from attacks against nuclear facilities."
Russia's state-owned nuclear energy provider, Rosatom, accused Ukraine of launching an "unprecedented series of drone attacks".
It said people were injured when a drone hit near the canteen at the site. A second drone struck a cargo area and the third hit a reactor dome, Rosatom said.
Andriy Kovalenko, head of a Ukrainian counter-disinformation unit, said Russia was firing drones and "pretending the threat to the plant and nuclear safety comes from Ukraine".
The IAEA team found there was some "scorching" on the top of a reactor dome and marks on water storage tanks. The attacks have "the potential to undermine the integrity" of reactor six at the Zaporizhzhia plant, Mr Grossi said.
Russia occupied the side in the early stages of its invasion, which it launched on February 2022. Russian forces also seized control of the area of the 1986 Chernobyl disaster.
Zaporizhzhia has kept running with Ukrainian staff on site, but in conditions the IAEA have said are unsuitable and pose safety risks. Kyiv and Moscow have been urged repeatedly to show restraint around the plant over fears of a nuclear disaster.
