FOR the second time in nine months, mysterious assailants yesterday used a deadly nerve gas to commit an indiscriminate act of violence in Japan.
The country, still recovering from the Kobe earthquake on Jan. 17, was stunned by the deliberate release of the gas, called sarin, in at least five locations along Tokyo's vast and efficient subway network. As of last night, six people had died and as many as 1,200 were hospitalized because of the incident.
The attack was in some ways reminiscent of the Feb. 26, 1992 bombing of New York's World Trade Center. Aside from the statistical similarities in the number of people killed and injured, both attacks struck at much-admired national symbols. Beyond the subway itself, yesterday's target seemed to be the stoic Japanese ''salaryman.''
The possibility that terrorists were responsible for yesterday's incident came as a shock to many Japanese.
Modern-day Japan has rarely, if ever, witnessed a politically motivated attack on innocent people. Terrorists here generally attack buildings, registering their opinion in symbolic, if violent, ways.
Just as Americans were surprised to see terrorism strike their homeland, many Japanese were upset to find that a mass killing had taken place in the nation's capital.
''I used to think Japan was a safe place, but now it's so scary,'' one woman told a TV interviewer.
A quick response
The Japanese government was criticized for its slow response to the Kobe earthquake, in which bureaucrats dithered as the city burned, but officials showed no lethargy yesterday.
The government's chief spokesman immediately decried the attack as ''indiscriminate killing'' and Prime Minister Tomiichi Murayama ordered a full investigation and emergency steps to aid victims only hours after the incident disrupted the morning rush hour.
Japan's military, prevented from early intervention in the Kobe quake by legalistic wrangling, was quickly ordered to assist the police yesterday, appearing on Tokyo streets in fatigues and helping decontaminate subway stations.
No one has claimed responsibility for the attack, only one of several factors that contribute to the mystery of the case.
Most troubling is that sarin has been used before in Japan. The compound was developed by Nazi scientists and reportedly employed by Iraqi forces to kill Iranian soldiers during the Iran-Iraq war and rebellious Iraqi Kurds.
On June 26 last year, in the hill town of Matsumoto, seven people died in their sleep when sarin drifted in through open windows late at night. Police have not yet solved that case.
Commentators immediately speculated yesterday about the possible connections, but Japanese law enforcement officials were silent about their investigation, saying only that the attack was deliberate.
It could hardly have been otherwise, since at least five receptacles containing sarin were left on subway trains at roughly the same time. The trains then continued their journey across the city, affecting subway riders in about 15 stations. All told, approximately 3,300 passengers complained of injury from the gas.
The assailants struck three subway routes, including the Hibiya Line, which connects the city's tony western suburbs with an area called Kasumigaseki, the home of Japan's imposing bureaucracies and the center of national power. Officials were forced to close Kasumigaseki Station yesterday morning.
One intriguing but inconclusive facet of the Matsumoto investigation concerns the discovery of sarin-related compounds at a village called Kamikuishiki, about 94 miles from Matsumoto. In July, village residents complained about the presence of an irritating gas, and investigators identified the cause as sarin residue late last year.
A shadowy group
The village is also home to some 350 adherents of a religious group called Aum Shinri Kyo, or Aum Supreme Truth, that was founded in the mid-1980s.
Press reports have linked the group with unsolved kidnappings and a July 1993 emission of noxious fumes from buildings it owns in Tokyo, so speculation arose about a connection between Aum Shinri Kyo and sarin.
A rival religious group, Kofoku no Kagaku (Institute for Research in Human Happiness), this month publicly accused Aum Shinri Kyo of being responsible for the Matsumoto poisoning, prompting the latter group to sue for defamation. Aum Shinri Kyo has also sued a pesticide maker in Kamikuishiki, claiming it was responsible for the sarin residue.
On Sunday, police in Osaka arrested three Aum Shinri Kyo members for kidnapping an Osaka University student, a charge the group rejects. Yesterday representatives of Aum Shinri Kyo also denied any role in the Tokyo incident.
Both of these groups are part of a religious trend in Japan called the ''new-new religions.''
These are groups and cults founded in the mid-1980s that combine apocalyptic fervor, messianic posturing, and shrewd marketing and proselytizing.
Eisho Omura, a professor of sociology at Osaka University who has written a book on the new-new religions, says the groups are part of what he calls a culture of agitation in Japan. ''The new religions and various new businesses today cause us to create a feeling of uneasiness and at the same time to provide the solutions to the uneasiness,'' he told one interviewer.
Although releasing nerve gas in the Tokyo subway system seems an effective way of spreading uneasiness, Professor Omura yesterday said he doubted any connection between Aum Shinri Kyo and the sarin incidents, saying the source of that accusation was ''suspicious.''