The operator of the Tokaido Shinkansen bullet train line says five passengers complained of sore eyes and throats after an aerosol was released inside a train car. Police are looking into the possibility that a passenger may have accidentally sprayed bear repellant when moving baggage.

Central Japan Railway Company says the incident occurred on the Hikari No. 518 headed for Tokyo on Saturday at around 7:15 p.m.

The company says an emergency button was pressed at Hamamatsu Station in Shizuoka Prefecture.

Fire department officials say five women between the ages of 7 and 32 had minor symptoms, and two were treated at hospital.

The incident prompted ambulances and fire engines to rush to Hamamatsu Station, where a command post was set up in front of the ticket gate.

The Shinkansen train operator asked all 770 passengers to change trains.

Based on eyewitness information, police suspect that a passenger may have accidentally released bear repellant spray after returning from a mountain trip and boarding the train at Hamamatsu Station.

The incident has caused delays in some other services on the Tokaido Shinkansen line.