The revised Antigang Law goes into effect Sept. 30, enabling authorities to crack down on the extent to which offices belonging to or affiliated with crime syndicates can be used.

The law is expected to be put into use immediately as a power struggle within the underworld triggered by the killing of the Yamaguchi-gumi's No. 2 man in August has set off a series of shootings across the country. The National Police Agency said it decided to introduce the revised law about one month earlier than scheduled because of the fatal shooting Aug. 28 of Masaru Takumi, the No. 2 man in the Yamaguchi-gumi, Japan's largest criminal organization, at a Kobe hotel.

The shooting was allegedly carried out by hit men from another powerful group within the syndicate. According to the NPA, the subsequent series of 22 shootings in 10 prefectures has been aimed at offices and homes affiliated with Nakano-kai, the Yamaguchi-gumi splinter group that was allegedly responsible for killing Takumi.

The NPA also plans to launch a one-month nationwide campaign in October to crack down on gangs and illegal handguns in a bid to prevent further shooting incidents. The police campaign will focus on uncovering gun trafficking routes in cooperation with customs and maritime safety authorities, as well as cracking down on protection rackets and other crimes targeting businesses, officials said. The campaign is aimed at eliminating gang organizations' sources of financing, they added.