Authorities in Japan are investigating the appearance of a drone containing possible radioactive material on the roof of Prime Minister Shinzo Abe’s office. Radioactive cesium was detected in the area after the drone was found carrying a bottle of liquid bearing the symbol for radioactivity. The drone’s discovery came as a Japanese court approved the restart of a nuclear power station as part of Prime Minister Abe’s push to return to nuclear power following the Fukushima meltdown in 2011.