Two explosions were heard in a residential area in Yokosuka, Kanagawa Prefecture late Friday in what is believed to be a guerrilla attack against the U.S. naval base in the port city, police said.On Sept. 17th, Jiji press [Japanese] reported that a group that called themselves "revolutionary army (革命軍)" sent a letter saying that they attacked the U.S. base. Japanese Police considers the group to be the anti-mainstream faction of Kakurokyo (革労協, 革命的労働者協会 or "Revolutionary Laborer's Association"), since rocket launchers found near the Yokosuka base were similar to those used by the group in the attack against Camp Zama last year as Mainichi reported [Japanese]. The anti-mainstream faction of Kakurokyo that is also called Sekisaisha-ha (赤砦社派, or "Red Fortress Co. Faction") has attacked the U.S. bases several times before. The following is a list of the guerrilla attacks that Sekisaisha-ha involved (from Japanese Wikipedia).
No one was hurt in the incident, which took place in a hilly area of the city at around 10:30 p.m., the police said.
The police said there were the traces of two rocket bombs being launched. Metal pipes, batteries and lead wires were found on the scene, they added.
The U.S. nuclear-powered aircraft carrier George Washington is scheduled to arrive at its new home port of Yokosuka on Sept. 25, replacing the carrier Kitty Hawk.
Activists opposed to the George Washington's deployment have been campaigning against its impending arrival.
July 3rd, 2000: Sekisaisha-ha attacked the U.S. Yokota base by rocket bomb.So far no one has been injured by the rocket bombs, and in many cases the bombs did not reach targets. However, it needs serious attention since they are launching bombs anyway. It is worth noting that they committed murders many times in the past. I am writing the background of this group below since there is little English-language information on the group on the Web.
April 12th, 2002: With a time ignite device, Sekisaisha-ha set fire to a train of Keisei Electric Railway.
Nov. 2002: Sekisaisha-ha attacked the U.S. Army Camp Zama by rocket bombs.
Feb. 24th, 2003: Sekisuisha-ha attacked the building of the Defense Agency of Japan by rocket bombs.
May 12th, 2003: Sekisaisha-ha attacked the U.S. Yokota base by rocket bombs.
April 3rd, 2003: Sekisaisha-ha attacked the U.S. Atsugi base by rocket bombs.
Feb. 17th, 2004: Sekisuisha-ha attacked the building of the Defense Agency of Japan by rocket bombs.
Nov. 7th, 2004: Sekisuisha-ha attacked the JSDF Asaka base by rocket bombs.
Feb. 12th, 2007: Sekisuisha-ha attacked the U.S. Army Camp Zama by rocket bombs.
According to Japanese Wikipedia, Kakurokyo is an anarcho-syndicalistic group that blasted a dormitory of the Metropolitan Police with two bombs in 1990. The explosion killed one policeman and injured eight policemen. The group split into two factions in 1999; One is the mainstream faction Gendaisha-ha (現代社派) and the other is the anti-mainstream faction Sekisaisha-ha. The two factions waged bloody conflict with each other from 1999 to 2004. The following is a chronicle of the conflict picked up from Japanese Wikipedia.
June 4th, 1999: Members of Gendaisha-ha attacked the leader of Sekisaisha-ha, Shigeki Yamada. Yamada was fatally injured but fortunately saved from death.
June 8th, 1999: Seventeen members of Sekisaisha-ha were arrested on a charge of assembling with offensive weapons. They were keeping weapons in the campus of Meiji University.
June 13th, 1999: Sekisaisha-ha declared 'war' against Gendaisha-ha.
July 2nd, 1999: On the road in Matsudo, Chiba prefecture, Sekisaisha-ha killed a director of Meiji University Coop, Yoshihiko Nagata, by repeatedly hitting his temples with hammers. He was one of the leaders of Gendaisha-ha.
July 21th, 1999: Gendaisha-ha attacked a staff member of Meiji University Coop, Ichiro Aikawa, who was a member of Sekisaisha-ha. He died on the next day.
July 22nd, 1999: Thirty-seven members of Gendaisha-ha were arrested on a charge of assembling with offensive weapons when they gathered in the campus of Meiji University.
Feb. 8th, 2000: Attackers of Gendaisha-ha assaulted the office of Sekisaisha-ha in Fukuoka prefecture. A sekisaisha-ha member Toshikazu Kataoka was killed. On the next day, Sekisaisha-ha assaulted the attackers of Gendaisha-ha in a train car in Kanagawa prefecture. The two attackers were repeatedly stabbed by broad-bladed kitchen knives in public. One was killed on the spot, and the other was fatally injured but saved from death.
Aug. 30th, 2000: Gendaisha-ha killed the chief secretary of the Meiji University Coop Labor Union, Emiko Katayama, by repeatedly stabbing her with knives in the JR Uguisudani Station in the rush hour. She was one of the leaders of Sekisaisha-ha.
Dec. 10th, 2000: Sekisaisha-ha killed a Gendaisha-ha member in Kiyose, Tokyo. He was a committeeman of the general affairs section of Kakurokyo
Feb. 16th, 2001: Four members of Gendaisha-ha were arrested on a charge of assembling with offensive weapons just in front of the house of a Sekisaisha-ha member, when they arrived there for assaulting the Sekisaisha-ha member.
May, 16th, 2001: Sekisaisha-ha members killed a Gendaisha-ha member in Yachimata, Chiba prefecture. He was a committeeman of the general affairs section of Kakurokyo.
June, 2nd, 2004: Three members of Sekisaisha-ha were attacked on the road in Taitoh Ward, Tokyo, by the Gendaisha-ha members armed with broad-bladed kitchen knives and hammers. A student of Chiba University who was the chairman of All-Japan Federation of Students' Self-Governing Associations (AJFSSGA) and a student of Komazawa University who was the former secretary of AJFSSGA were killed there.
After the last incident in 2004, it is believed that the conflict between Gendaisha-ha and Sekisaisha-ha reached a settlement. So, they may start to attack facillities of the U.S. military and JSDF more often than before.