Rafael Grossi, director general of the International Atomic Energy: 'We must act now to prevent the threat of a severe nuclear accident.' Photograph: Sergei Ilnitsky/EPA Nuclear experts have warned that fighting in Ukraine poses a growing threat to Europe’s biggest atomic power plant, as a Russian warlord said his mercenaries had been promised more ammunition after he threatened to withdraw from the fight for the city of Bakhmut. Deadly shelling and gun battles continued in eastern Ukraine over the weekend, while near the Russian city of Nizhny Novgorod, a prominent ultranationalist politician and writer who fought for Moscow in Ukraine,...