The nation's two largest underworld syndicates reached a truce Thursday following recent shootings that sparked fears of a full-scale turf war and prompted police to raid one of the groups believed involved in the violence.
Kobe-based Yamaguchi-gumi and Tokyo-based Sumiyoshi-kai separately reported to the Metropolitan Police Department on Thursday afternoon that they made peace in the wake of Monday's gunning down of a senior Sumiyoshi-kai member, MPD officials said.
Investigators hope the recent violence -- believed part of a turf war between the two crime syndicates -- will halt with Thursday's truce, but said they will continue to monitor the mob's activities.
Police will further crack down on senior and regular members to prevent a full-scale gangland war.
Ending a yearlong hiatus in gang violence, Ryoichi Sugiura, 43, a senior member of Kobayashi-kai, a gang affiliated with Sumiyoshi-kai, was shot to death Monday in Tokyo's upscale Nishi-Azabu district.
The killing is believed to have prompted three more shooting incidents this week targeting gang headquarters in Tokyo.
No arrest has been made in the slaying, and no other injuries have been reported.
Police Wednesday arrested two Sumiyoshi-kai members suspected of firing shots into the front door of an office used by rival Yamaguchi-gumi.
About 40 officers, many in full body armor, raided Sumiyoshi-kai offices Thursday in an attempt to prevent escalating violence.
Police on Wednesday searched the homes and other places visited by the two arrest suspects.
They seized a semiautomatic pistol from a location in Setagaya Ward and are investigating whether the firearm had been used in any of the shootings.
Police refused to comment on the motive for the shootings. Shooting doors or windows of a rival gang's offices is the trademark of underworld retaliation.
On Wednesday, senior members of Yamaguchi-gumi were in Tokyo for a meeting with their Sumiyoshi-kai counterparts, according to sources involved in the investigation.
Yamaguchi-gumi, which with 21,000 members is Japan's top underworld syndicate, has frequently been involved in turf wars with the 8,000-strong Sumiyoshi-kai in recent years.
Police say the tension is a result of the rapid expansion of Kobe-based Yamaguchi-gumi's into Tokyo, Sumiyoshi-kai's traditional base.
Yakuza, like mobsters worldwide, are involved in extortion, gambling, the sex industry, gunrunning, drug-trafficking, and real estate and construction kickback schemes.