Ukraine’s Energy Ministry said on Wednesday that a Russian strike has cut off power to the protective structure covering the destroyed reactor at the Chernobyl nuclear power plant, the site of the 1986 disaster.

In a statement posted on Telegram, the ministry said, “Due to a power surge, electricity supply to the New Safe Confinement has been cut off. This is the main structure that isolates the destroyed Unit 4 and prevents radioactive leakage,” according to AFP.