A presidential adviser says Ukraine lost control of the Chernobyl nuclear site, where Ukranian forces had waged a fierce battle with Russian troops. Adviser Myhailo Podolyak told The Associated Press that Ukrainian authorities did not know the current condition of the facilities at Chernobyl, the site of the world’s worst nuclear disaster. “After the absolutely senseless attack of the Russians in this direction, it is impossible to say that the Chernobyl nuclear power plant is safe,” he said. Ukrainian President Volodymyr Zelenskyy had announced several hours earlier Thursday that Russian forces were trying to seize the Chernobyl nuclear plant. A nuclear reactor at the plant 130 kilometers (80 miles) north of Ukraine’s capital, Kyiv, exploded in April 1986, sending a radioactive cloud across Europe. The exploded reactor was covered by a protective shelter several years ago to prevent radiation leaks. A Ukrainian official said Russian shelling hit a radioactive waste repository and an increase in radiation levels was reported. The official spoke on condition of anonymity to discuss the sensitive matter. It was not immediately possible for experts to access the repository to assess damage before Russian forces overtook the site.