Police burst into the building in Yokohama, just south of the Japanese capital, after the gunman stopped talking to them and found him dead with a gunshot wound to the head, said police spokesman Shigeki Umehara.

While earlier talking with police, the gunman identified himself as Kenji Hayashi, a 62-year-old member of the third-largest gangster group in Japan, the Inagawa-kai.

The three wounded men were rushed to the hospital and one was in critical condition, according to prefectural police spokesman Katsuzo Nakayama. The two others were conscious.

Guns are strictly controlled in Japan, and shootings are rare. Shootings that do occur are often linked to the yazuka, or Japanese mafia, who typically make their income from extortion, gambling, prostitution, gunrunning, drug-trafficking and construction kickback schemes.

In 2007, the mayor of Nagasaki, Iccho Ito, was shot to death at close range by a gangster outside a train station while campaigning for re-election for his fourth term.

Later that year, a 37-year-old man killed two people and wounded six others in a shooting spree at a sports club in southern Sasebo city before killing himself outside a church.