The Metropolitan Police Department ordered every police station in Tokyo on Thursday to be on full alert against terrorist attacks against the French Embassy and other such facilities in the capital.
The high alert comes in the wake of a terror attack in Paris on Wednesday, when masked gunmen killed 12 people at the office of a satirical weekly.
According to the police, there are between 10 and 20 places in Tokyo that are at risk, including the French Embassy in Minato Ward and the Tokyo branch of major French news agency Agence France-Presse in Chuo Ward.
Tokyo police have long had a presence at large public facilities, such as train stations and airports.
However, every Tokyo police station has been told to boost security, including increasing patrols, since the attack in Paris.