Tokyo police are stepping up security for the Imperial procession taking place later on Sunday to mark Emperor Naruhito's accession to the throne.
The Tokyo Metropolitan Police Department has set up a "top security division" under the leadership of its chief. About 26,000 officers, including 3,000 from other prefectures, are being mobilized.
The motorcade parade was originally planned for October 22. But the government postponed it to focus on recovery in areas affected by Typhoon Hagibis.
Strict baggage inspections will be in place, as firecrackers were thrown at the procession of the then Emperor Akihito to mark his enthronement in 1990.
Spectators will also be checked with metal detectors before entering fenced-off areas for viewing the procession. They are banned from bringing items such as knives, bottles and cans.
Roads linked to the parade route will be blocked with large police vehicles to prevent terrorist attacks using cars.
Police are also deploying a special unit to deal with suspicious drones, as well as an emergency response team equipped with firearms to counter terrorist attacks.