Tokyo:
Japan on Friday marked 20 years since the first deadly sarin gas attack by a doomsday cult, which later terrorised the nation by releasing the chemical on Tokyo's subway.
The 1994 attack in mountainous Matsumoto is regarded as the world's first terror act using nerve gas against civilians in peace time, and targeted a judge handling a civil suit involving the home-grown group.
Yoshiyuki Kono, who reported the incident to authorities but was erroneously regarded as the prime suspect by media at the time, told national broadcaster NHK that society must remember.
"It's impossible to stop memories from fading... But there were lessons learned from it, and I think we should make good use of those lessons," he said.
On the night of June 27, 1994, members of the Aum Supreme Truth cult released the Nazi-invented sarin in Matsumoto city, with the dual focus of killing the judge and testing the efficacy of the nerve gas.
The judge did not die, but the attack killed seven others immediately, followed by Kono's wife, who died in 2008 after years of suffering from the damage to her nerves inflicted that night.
The attack horrified and puzzled investigators unfamiliar with the nerve gas, which injured some 600 others in the city.
The cult, led by half-blind guru Shoko Asahara, continued its activities aimed at toppling Japan's social order, believing doomsday was imminent.
On March 20, 1995, the cult orchestrated the notorious sarin gas attacks on the Tokyo subway, killing 13 people and injuring thousands.
Thirteen Aum members are on death row after being convicted over the subway attack.
Asahara peddled a blend of Buddhist and Hindu dogma mixed with apocalyptic messages.
He developed an obsession with sarin gas and became paranoid that his enemies would attack him with it.