A senior Russian official said on Thursday that Russia prevented a Ukrainian attack on the Russian-controlled Zaporizhia nuclear power plant in southern Ukraine.

Ukraine and Russia accuse each other of bombing Europe’s largest nuclear power plant.

Ukrainian forces “continue to bomb the Zaporizhzhya NPP with Western weapons, which could lead to a global catastrophe,” said the Secretary of the Security Council of Russia Mykola Patrushev, an ally of Russian President Vladimir Putin.

Patrushev said that the Russian special services prevented, in his words, a “terrorist attack” at the plant.

Ukraine’s state-run nuclear company said Thursday that Russian bombing had damaged high-voltage lines at the plant and that it had been disconnected from the country’s power grid.