Biochemical scare at Tokyo metro

Fire-fighters trained to cope with biochemical terrors were rushed to a Tokyo metro station on Wednesday when a male passenger dropped a bottle filled with an industrial acid onto the floor of a train.

The plastic bottle cracked on impact, unleashing a chemical odour and sickening four passengers on the train when it was stopping at the Nihonbashi station in the city centre, police and metro officials said.

The hydrochloric acid spilled onto the feet of two passengers and they were taken to a hospital by ambulance for treatment of slight burns, a Tokyo Metro Co. spokeswoman said.

Two other passengers felt ill but were able to go home after resting for a while, she said.

"Police said the case was not of a criminal nature," the metro official said.

A metropolitan police spokesman said a 20-year-old mason accidently dropped the bottle of hydrochloric acid, which has many legitimate industrial uses.

The metro station was shut down for one and a half hour while fire-fighters, including the Haz-Mat (hazardous material) Unit of the Tokyo Fire Department, retrieved and examined the bottle.

The same unit was also deployed after the Sarin nerve gas attacks on metro trains by the Aum Supreme doomsday cult in 1995. The attacks killed 12 people and injured thousands.

"We dispatched the unit in response to reports about a suspicious odour. It was in keeping with our standard operating procedure," said a press officer at the fire department.