Ukraine’s nuclear ghosts have been stirred up again after a drone armed with a warhead hit the protective outer shell of the plant at Chernobyl, the site of the world’s worst nuclear accident. The strike on Friday did not breach the plant’s inner containment shell and radiation levels did not increase.

Ukraine’s President Volodymyr Zelensky announced Friday that an armed Russian drone struck and pierced the exterior protective shell over the site of the 1986 Chernobyl nuclear disaster.

A drone armed with a warhead hit the outer shell of Ukraine’s Chernobyl nuclear plant, briefly starting a fire, in an attack Kyiv blamed on Russia.