TOKYO -- Amid a spate of robberies in the Tokyo metropolitan area, there were also suspected related cases in Tochigi Prefecture and Sapporo, where an individual believed to be one of the leaders in several of these cases went by the name of 16th century Japanese warlord Oda Nobunaga, an investigative source has revealed to the Mainichi Shimbun.

Police authorities are investigating the involvement of the same group of leaders in incidents that took place over a wide area.

According to the source, in the 11 cases that occurred in Tokyo and surrounding Saitama, Chiba and Kanagawa prefectures since August, the perpetrators are believed to have received instructions from at least 30 accounts through a highly confidential communications app.

Among the newly emerged cases was an attempted home invasion in Haga, Tochigi Prefecture, on Sept. 11. In this incident, the leaders are believed to have used accounts with the names of historical figures such as samurai general Akechi Mitsuhide and shogun Tokugawa Ieyasu, in addition to Oda Nobunaga.

The name Oda Nobunaga was also reportedly used in the abduction and confinement case involving injury in which a man was taken from his home in Tokyo's Nerima Ward on Sept. 10, the day before the Tochigi incident.

On Oct. 5, there was also a robbery and battery case in Sapporo's Toyohira Ward. Someone broke into a house by smashing a window, and the resident, an elderly man, was tied up with adhesive tape. This kind of operation is common to a string of incidents in the Tokyo metropolitan area.

Meanwhile, it was confirmed that an account under the name of 19th century novelist Natsume Soseki was used in all of the three recent incidents of robbery involving injury that occurred in the capital's Nerima Ward and suburban city of Kokubunji, as well as in the Saitama Prefecture city of Tokorozawa, in September and October. These cases drew attention to the other robberies seen across the country.

Meanwhile, the name Akanishi is believed to have been used in four other incidents in August and September in Saitama's Nishi Ward, the Chiba Prefecture city of Yachiyo and the Kanagawa Prefecture cities of Atsugi and Kamakura. The name of the popular cartoon character Dr. Hiriluk was also confirmed to have been used in several cases.

Nine accounts were used in the Sept. 28 robbery in Tokyo's Nerima Ward, and it is possible that the leaders each used different accounts.

The series of incidents is believed to be expanding beyond the greater Tokyo area. Police have received information that cases in the Tohoku and other regions are also suspected to be related, and they believe that the perpetrators, who applied for "shady part-time jobs," are committing robberies and other crimes in a wide area while changing members.

The Metropolitan Police Department and the Saitama, Chiba and Kanagawa prefectural police forces set up a joint investigation headquarters on Oct. 18 to identify the leaders.

(Japanese original by Ayumu Iwasaki and Kengo Suga, Tokyo City News Department)