TOKYO -- The police search of a religious sect's properties focused yesterday on a three-story building that believers say is one of the organization's most holy sites but that authorities say contains a sophisticated chemical laboratory capable of producing large quantities of nerve gas.
As snow fell on the placid village where the sect had its main complex, near the foot of Mount Fuji, about 1,000 police officers conducted their search and carted off more than 100 drums that were labeled as containing sodium fluoride, an ingredient of the nerve gas sarin.
The police justified the search on the grounds that they were gathering evidence that sect leaders were planning to make sarin in "preparation for murder."
It was the first time the compound has been officially linked to the deadly subway attack in Tokyo last week. Searches on Wednesday were made on the pretext of unrelated kidnapping cases.
Leaders of the sect, Aum Shinrik- yo, vigorously deny that they ever made sarin. Yesterday they repeated assertions that they were the victims -- of sarin poisoning by U.S. military aircraft -- and that the Japanese government itself probably staged the subway attack to frame the sect.
The police search of the sect's properties began Wednesday and turned up huge quantities of chemicals that can be used to make sarin and tabun, another kind of nerve gas. But one puzzle has been where the group could synthesize the gas.
The authorities apparently think that they have found the answer in the laboratory that they searched yesterday. Reporters have not been allowed inside, but some accounts suggest that it is a sophisticated lab.
A network of thick pipes and three cooling towers, each resembling the central air conditioner for a large building, are visible outside the building, and the police say they are connected to the laboratory.
The ventilation system and fixtures are said to be those of a modern laboratory with computer-controlled systems, but some Japanese news reports said that some chemistry equipment appeared to have been removed recently.
The lights had been dismantled, perhaps to hamper a search, but police confiscated some chemistry equipment and several hundred reference books, news reports said. In a small building next door, the police reportedly found optical analysis equipment that is used to examine gases and costs hundreds of thousands of dollars.
The laboratory was described by the sect as its "science and technology agency," but there appears to have been some effort to keep its existence a secret. The entrance was hidden behind an alcove containing an altar, and the area was described as so holy that many sect members were not allowed to enter.
One reason the site is described as so holy is that it contains a sanctuary that is said to contain some of the remains of Buddha.
The sect's guru, Shoko Asahara, supposedly brought them to the site after making a pilgrimage to the Indian subcontinent.
The search is expected to continue today.