Tokyo: Japan is launching an investigation into the landing of a drone on the roof of Prime Minister Shinzo Abe`s office building, a government spokesman said, after media reported "minuscule" traces of radiation were found.
Japan Chief Cabinet Secretary Yoshihide Suga said police were investigating Wednesday`s incident and that the government may consider new regulations on drones.
Police found the radiation to be low enough not to be harmful to humans, media said.