A man set himself ablaze on board a moving bullet train in Japan Tuesday, killing himself and a woman, in an unprecedented incident on a network with an enviable safety record, Yahoo! News reports.

The super-fast Nozomi train was forced to come to an emergency stop between JR Shin-Yokohama and Odawara stations after the incident.

The man, who some witnesses said appeared to be mentally disturbed, doused himself and parts of the train's interior with a flammable liquid before igniting it with a cigarette lighter at the front of the train, just outside the driver's compartment, passengers told Japanese television networks.

Aerial footage showed emergency crews and railway workers surrounding the train. Twenty-six people were treated for injuries including burns and smoke inhalation, the local fire department said, according to the New York Times.

Officials have given no indication of the man's motives but are treating the incident as a suicide.

This incident will be profoundly shocking to the Japanese. Japan is renowned for being a safe country and the bullet train is the safest in the world, according to BBC News. In fact, it hasn't recorded a single fatality since it started operation more than 50 years ago.

While Japan is no stranger to suicide - last year the country reported the highest rate of suicide in the world - self-immolations are relatively rare.

Officials are investigating the man's motives.