A Russian drone attack has hit the radiation shelter protecting Chernobyl's damaged nuclear reactor, Ukrainian President Volodymyr Zelensky has said. The overnight strike at the nuclear plant, which is the site of the world's worst nuclear accident, caused a fire that has since been extinguished, he added.

The outer shell that was struck is a protective cover built in 2016 over a heavy concrete containment structure. Soon after the 1986 disaster, the inner layer (in which there was no indication of a breach on Friday morning), was placed on the plant’s fourth reactor. The containment shells seek to prevent radiation leaks.