Tokyo Metropolitan Police on Saturday arrested a female on suspicion of assault, following nine commuters taken to hospital for smelling a "caustic" substance at a railway station.

According to public broadcaster NHK, police arrested Yumiko Tsukakoshi, 36, who resides in Tokyo's western Nerima Ward, on suspicion of carrying out the attack on Sept. 28 on the Seibu Shinjuku Line platform at the Takadanobaba Station.

Investigators analyzed video footage taken at the station and the victims' testimony before having the suspect.

Police searched Tsukakoshi's home in Nerima retrieved what they described at least one can resembling pepper spray and arrested the suspect who has denied the allegations and claimed she was nowhere near the vicinity when the incident occurred at the busy Tokyo station during rush hour.

Following the commuters complaining of "feeling bad" after smelling something "caustic" and similar to paint thinner or another chemical, emergency personnel were quickly dispatched to the station.

First responders and officials at the time believed that a substance such as paint thinner could have been dispersed at the station, or some form of chemical accidentally spilled at the busy transportation hub in central Tokyo.

Nine people were taken to a separate room at the station to receive emergency medical care by Seibu Railway staff, and subsequently taken to hospital to receive further treatment, local media reported.

One 32-year-old businessman claimed he was sprayed directly with a "noxious substance."

The area around the station was quickly cordoned off, with certain access restricted to rescue officials, but while a heavy presence of police, fire department and ambulances remained on the scene carrying out investigations for some time, the incident did not cause the train's operator to suspend its service.

The incident, police officials said, was taken extremely seriously in light of a sarin gas attack on subway lines here two decades ago, and local commuters were quoted as saying they were in a state of shock following the attack.

On March 20, 1995, members of the Japanese cult Aum Shinrikyo, as it was named at the time, carried out coordinated sarin gas attacks on several lines of the Tokyo subway system during rush hour, killing 12 people and seriously injuring dozens of others.

While Aum's attack was apparently aimed at government personnel, the latest incident remains motiveless, although police said they are probing Tsukakoshi's potential motives and haven't ruled out cult affiliations, mental health issues, or personal grievances.

Source : XINHUA