The head of the International Atomic Energy Agency is warning of the heightened risk of a nuclear catastrophe after Ukrainian soldiers pressed their counteroffensive deeper into Russia and close to the Kursk nuclear power plant. On Tuesday, IAEA chief Rafael Grossi said after a tour of the aging nuclear facility that Ukraine and Russia must cease fighting around all nuclear sites, including Kursk and the Russian-occupied Zaporizhzhia power plant in Ukraine. Grossi warned the Soviet-era Kursk nuclear plant’s reactors are not protected by the sort of containment domes typically found in modern nuclear facilities, making them especially vulnerable to damage from missiles or artillery fire.