A senior Japanese National Police Agency official has instructed prefectural police departments to join efforts to fully investigate a recent series of robberies and round up all of the perpetrators.

The head of the Criminal Affairs Bureau, Watanabe Kuniyoshi, spoke at a meeting on Friday attended by senior police officials from the 14 prefectures concerned across the country.

Recent robberies in the prefectures are suspected to have been committed by the same group.

Watanabe instructed the attendees to keep two points in mind.

First, he said that although a number of suspects have been detained as perpetrators, the mastermind and other senior-level suspects must also be arrested.

Second, he called for various divisions of the police departments to coordinate efforts by sharing information and to carry out speedy investigations.

Watanabe said the robberies have had a large impact on society and have increased anxiety among the public.

He went to say that the true value of Japanese police investigations is now being questioned.