THE head of the United Nations’ atomic watchdog condemned Sunday’s drone strike on one of six nuclear reactors at the Russian-controlled Zaporizhzhia nuclear power plant in Ukraine.

Rafael Mariano Grossi said the attacks “significantly increase the risk of a major nuclear accident.”

In a statement on X (formerly Twitter), Mr Grossi confirmed at least three direct hits against the ZNPP main reactor containment structures took place.

“This cannot happen,” he said.

Russia blamed the attack on Ukraine, but the UN’s International Atomic Energy Agency didn’t assign blame.

Andrii Yusov, the spokesperson for Ukraine’s military intelligence agency, insisted there had been no attack, saying Russian forces routinely fabricate strikes on the plant.

Mr Grossi said it was the first such attack since November 2022, when he set out five basic principles to avoid a serious nuclear accident with radioactive consequences.

Officials at the plant said the site was attacked by Ukrainian military drones, including a strike on the dome of the plant’s sixth power unit.

According to the plant authorities, there was no critical damage or casualties and radiation levels at the plant were normal.

Later on Sunday, however, Russian state-owned nuclear agency Rosatom said that three people were wounded in the “unprecedented series of drone attacks.”

The International Atomic Energy Agency (IAEA) said on Sunday that its experts had been informed of the drone strike and that “such detonation is consistent with IAEA observations.”

In a separate statement, the IAEA confirmed the physical impact of drone attacks at the plant, including at one of its six reactors. One casualty was reported, it said.

“Damage at unit 6 has not compromised nuclear safety, but this is a serious incident with potential to undermine integrity of the reactor’s containment system” it added.

The power plant has been caught in the crossfire since Moscow invaded Ukraine in 2022 and seized the facility shortly after.

The IAEA has repeatedly expressed alarm about the nuclear power plant, Europe’s largest, amid fears of a potential nuclear catastrophe.

Both Ukraine and Russia have regularly accused each other of attacking the plant, close to the front line.

Its six reactors have been shut down for months, but it still needs power and qualified staff to operate crucial cooling systems and other safety features.

Vyacheslav Gladkov, governor of Russia’s Belgorod region, said a girl died and four other people were wounded when the debris of a downed Ukrainian drone fell on a car carrying a family of six.