Moscow and Kyiv accused each other of starting a fire on the grounds of Europe's largest and now Russian-occupied Zaporizhzhia nuclear power plant in Ukraine on Sunday, with both sides reporting no sign of elevated radiation.

The head of the U.N.’s atomic watchdog agency on Sunday condemned a Ukrainian drone strike on one of six nuclear reactors at the Russian-controlled Zaporizhzhia Nuclear Power Plant in Ukraine, saying such attacks “significantly increase the risk of a major nuclear accident.”