"We have been informed that there was a passenger in a car on the train who covered him or herself with oil and set it on fire," said a JR Central spokesman.
The train -- a super-fast Nozomi bullet train -- was travelling from Tokyo towards Osaka when the fire broke out near Odawara, west of Tokyo.
"We received information indicating that a fire broke out near a toilet and two people were in cardiopulmonary arrest," a spokesman for Odawara Fire Department said.