A drone armed with a warhead hit the outer protective 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.

President Volodymyr Zelensky of Ukraine called the damage “significant” but said there were no signs of radiation leaks. A Kremlin spokesman denied that Russia had carried out the strike.

A Russian drone attack has hit the radiation shelter over the damaged reactor at the Chernobyl nuclear power plant, Ukrainian President Volodymyr Zelensky has said. The overnight strike hit the shelter of the plant's destroyed former fourth power unit, causing a fire that has since been extinguished, he added. Russia has not yet commented.