Two people were feared dead and two others seriously injured after a man apparently set himself on fire aboard a moving shinkansen bullet train in Japan on Tuesday.

"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," a spokesman for operator JR Central told AFP.

The Yomiuri Shimbun daily said a blast was heard from a toilet stall, with the emergency bell pressed soon afterward, which brought the train to a halt.

Media reported that the driver of the train found the still-burning body of a man after the emergency stop.

The train -- a super-fast Nozomi bullet train -- was travelling from Tokyo towards Osaka, reportedly with around 1,000 passengers on board, when the fire broke out near Odawara, southwest 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.

"Other passengers were also injured," he said, adding that two were in a serious condition.

NHK reported the two people feared dead were found on the floor of the first car, but at opposite ends of the carriage.

TV Asahi said the second person found lying on the floor was a woman who had been overcome by smoke.

The network said the number of injured people was expected to rise as first responders treated more and more people suffering from the effects of smoke inhalation.

The fire erupted at around 11:30 am (0230 GMT) when the train was about 70 kilometres (45 miles) from the capital.

Television pictures showed all the doors on the stationary train were open and passengers were being carried out on stretchers.

Prime Minister Shinzo Abe set up a task force to respond to the incident, TV networks said.

Japan's ultra-efficient shinkansen train network connects cities along the length and breadth of the country.

Despite the huge volume of passengers it serves, the network operates with an enviable punctuality rate. It also has an unparalleled safety record, with no one ever having been killed in a crash in its half century of service.

The first service connecting Tokyo and the western commercial hub of Osaka, some 500 kilometres away, began in 1964, as Japan prepared to host the Olympic Games.

An average of more than 400,000 passengers use the service daily, travelling at speeds of up to 285 kilometres per hour, with around 300 trains running in both directions each day.

When the system marked its 50th anniversary last year, the Tokyo-Osaka line had carried a total of 5.6 billion passengers, with trains travelling a cumulative 2 billion kilometres, enough to circle the globe 50,000 times.