In the past few weeks, a mysterious caravan of white vehicles carrying white-robed people has been traveling around the country, causing disputes with residents along the way. The group calls itself Pana Wave Laboratory, a doomsday cult that evokes memories of crimes committed by members of the Aum Shinrikyo cult. This week's police raids were only to be expected.

The Metropolitan Police Department and other prefectural police authorities searched white-camouflaged vehicles as well as cult facilities in Tokyo and four other prefectures: Fukui, Yamanashi, Okayama and Fukuoka. Police also questioned key members of the cult and confiscated many documents and materials. The trigger for conducting the raids was suspicion that some group members had committed a relatively minor law violation: making false car registrations.

At the moment, the cult is not suspected of any serious offense. Nevertheless, it has created suspicion and even alarm, in large part because very little is known about this quasi-religious organization, particularly its activities and finances. Police should speed up their investigation to find out what it is up to. One lesson from Aum Shinrikyo is that its heinous crimes, including the sarin gas attack on a Tokyo subway in March 1995, could have been prevented if police had begun investigating the group sooner.