On Thursday, Russian attacks were reported across a significant portion of Ukraine. Shelling and missile strikes reportedly damaged infrastructure, including the electrical supply to Europe’s largest nuclear reactor.

After Russian shelling damaged the last high voltage lines, leaving it with only diesel generators, the Zaporizhzhia nuclear power facility in southern Ukraine was once more cut off from the electricity grid, according to the Ukrainian nuclear company Energoatom.

The plant, in Russian hands but operated by Ukrainian workers, has 15 days’ worth of fuel to run the generators, Energoatom said. Its reactors need power to keep the fuel inside cool and prevent a meltdown.

A senior official in Moscow said Russian special forces had prevented a Ukrainian attack on the plant. Russian Security Council Secretary Nikolai Patrushev, a close ally of President Vladimir Putin, also said Ukrainian forces “continue to shell the Zaporizhzhia nuclear power plant with Western weapons which could lead to a global catastrophe”.

Both sides have repeatedly accused the other of shelling the plant, accusations that both deny.

Russian strikes were also reported in Kriviy Rih, in central Ukraine, and in Sumy and Kharkiv, in the northeast. There was heavy fighting in the eastern regions of Luhansk and Donetsk.

“The enemy is trying to keep the temporarily captured territories, concentrating its efforts on restraining the actions of the Defense Forces in certain areas,” Ukraine’s general staff said on Thursday.

Russia has said it has targeted infrastructure as part of what it calls its “special military operation” to degrade the Ukrainian military and remove what it says is a potential threat against Russia’s security.

As a result, Ukrainian civilians have endured power cuts and reduced water supplies in recent weeks. Russia denies targeting civilians, though the conflict has killed thousands, displaced millions and left some Ukrainian cities in ruins.

Foreign ministers from the G7 group of rich democracies will discuss how best to coordinate further support for Ukraine when they meet on Thursday in Germany.