A drone armed with a warhead hit the protective outer shell of Ukraine's Chernobyl nuclear plant early Friday, punching a hole in the structure and briefly starting a fire, in an attack Kyiv blamed on Russia.

A radiation shelter on the Chernobyl nuclear power plant site was damaged by Russian drones, according to Ukrainian officials. The Ukrainian government says a fire broke out after a Russian drone struck the shelter of the destroyed power unit at the plant.

Russian troops occupied Chernobyl in the opening weeks of the war, raising fears that they could cause damage and trigger a radioactive accident. Since the Russians' withdrawal in late March 2022, Ukraine has mounted a drive to install further protections at the defunct site, including anti-drone systems and anti-tank barriers.