About 500 officers of the Metropolitan Police Department were mobilized Sept. 18 to search about 100 offices and locations in Tokyo related to the Yamaguchi-gumi and Nakano-kai crime syndicates on suspicion of violation of the Firearms and Swords Control Law.

The sweep resulted in the arrests of 11 gangsters on suspicion of illegal possession of stimulant drugs and other charges. The latest raids took place after a series of shootings broke out following the assassination of the Yamaguchi-gumi's No. 2 man in Kobe last month.

The hit was allegedly carried out by the Nakano-kai, a gangster group that was formerly part of the Yamaguchi-gumi, in what police say is an internal power struggle. The Yamaguchi-gumi is the country's largest gang. The MPD conducted similar raids Sept. 10.