Police on Saturday opened an investigation into an incident Friday in which two shots were fired at a teachers' union office in Hiroshima.
The shots were fired at the windows of the office, which is on the third floor of a building in Hiroshima's Higashi Ward, around 9:35 p.m. on Friday. One of the bullets penetrated a ceiling, while the other was found embedded in a windowpane, they said.
Three people were in the office at the time, but nobody was injured.
Later that day, a man called the Asahi Shimbun headquarters in Osaka to claim responsibility, identifying himself as a member of a rightwing organization that goes by the name The Patriotic Forces Detached Squad To Punish Traitors.
"I shot two bullets at the Japan Teachers' Union in Hiroshima," an Asahi official quoted the man as saying. "I will attack the union all over Japan."
The group the man claimed to represent was also cited by a caller to another Asahi Shimbun office earlier this month. That man claimed responsibility for shooting at Aum Shinrikyo facilities in Tokyo and Osaka in May and June, the police said.
According to the Hiroshima teachers' union, rightwingers have staged protests close to its offices this month.
