Five men arrested in connection with a series of shootings practiced at a rifle range in Guam in April, police sources said Monday.

Ichiro Murakami, 54, head of what is considered a rightist group, Token Tomo-no-kai (Japanese Sword Club), and four of its members spent some $850 for the practice at a shooting range on Guam, apparently to get used to handling guns in preparation for the subsequent series of attacks, the sources said.

The five are believed to have been involved in four shooting attacks spanning from the end of May to the end of July, targeting an Aum Shinrikyo office in Tokyo and an office in Niigata of a pro-Pyongyang Korean residents' association.

According to the sources, Murakami, together with seven members of his sword fanciers' group, went to Guam in early April and stayed at the same hotel.

Among the seven were Ryuji Nakamura, 32, Fumio Nonoyama, 52, Tatsuya Hattori, 40, and Eiji Shikano, 48, who were arrested in connection with the shootings.

The sources said payment records show that Murakami used a credit card to pay about $850 to the U.S.A. Gun Club during their stay.

At that particular range, the minimum fee for using guns with real ammunition is around $20.

Among those who went on the trip is a 54-year-old man who committed suicide Saturday after being questioned by police over the shooting at the Niigata headquarters of the General Association of Korean Residents in Japan (Chongryun).