The Kyodo news agency reported, citing investigative sources, that the drones flew above the site, flashing red and white lights, late on Thursday, a day after Emperor Naruhito ascended the throne.
The outlet noted that Japanese laws prohibited flying drones in Tokyo, central areas of other cities, densely built-up areas and in the vicinity of airports.
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On 1 May, Japan's New Emperor Naruhito vowed to carry out his duties as the nation's symbol in accordance with the constitution, expressing hope for the happiness of Japanese people and peace. Naruhito has officially been named the new emperor of Japan, commencing a new era in the country's history, named "Reiwa", which can be translated as "beautiful harmony".
