A drone armed with a warhead hit the protective outer shell of Ukraine's Chernobyl nuclear plant early Friday, damaging the structure and briefly starting a fire, in an attack Kyiv blamed on Russia. The Kremlin denied it was responsible.

Ukraine said a Russian drone crashed into the containment structure, starting a fire, but so far radiation levels have stayed constant.

A Russian drone struck the former nuclear power plant at Chernobyl in an attack overnight into Friday, Ukrainian President Volodymyr Zelensky has said. The strike hit the concrete shelter that covers the plant’s destroyed former fourth power unit,