A local gang boss was sentenced Friday to 20 years in prison for ordering firebomb attacks on the home of Prime Minister Shinzo Abe in Shimonoseki, Yamaguchi Prefecture, in 2000.

Motoshi Takano, 57, the local branch chief of the Kudo-kai crime syndicate based in Kitakyushu, ordered junior members to throw gasoline bombs into Abe's home and the office of his supporters five times between June and August 2000, according to the Kokura branch of the Fukuoka District Court.

Shimonoseki is Abe's electoral base.

The court sentenced local real estate broker Saichi Koyama, 69, to 13 years for asking Takano to carry out the attacks. Senior gang member Toshihiko Ikeda, 60, was given 12 years for executing them.

Koyama came up with the idea of asking the mob to carry out the attacks after a local aide of Abe's refused to give Koyama cash in return for supporting a Shimonoseki mayoral candidate in 1999, prosecutors said.

At the trial, Takano admitted his guilt, Koyama said Takano acted alone, and Ikeda denied being involved in the crimes.

Prosecutors demanded a life term for Takano, 15 years for Koyama and 13 for Ikeda.

Two other mobsters, one a driver and another who played a role in the attacks, have already been convicted.

Takano has also been charged with committing arson in Chiba Prefecture in 2001.