Tourists decked out in 'Mario Kart' costumes and driving rented go-karts will soon be required to fasten their seat belts after a spate of accidents. Photo: Japan Times

TOKYO: People dressed as Super Mario tearing round the streets of Tokyo in go-karts will have to buckle up, Japanese authorities said Thursday, following a series of accidents.

Visitors to Tokyo are often stunned to see convoys of karts driven by people -- often tourists -- dressed up as Mario and other popular Nintendo characters screaming around the busy streets of the world's most populous city.

Unlike many countries, Japan has no ban on people driving go-karts on public highways.

But following three accidents over the past year, the transport ministry has decided to enforce the wearing of seatbelts for such vehicles.

Currently, the vehicles have no seatbelts and drivers are not required to wear helmets, a ministry official who did not wish to be named told AFP.

"It's dangerous as other cars cannot see them because of their low height," he added.

The ministry is looking to implement the regulations in a few years.

Under the proposed new rules, go-karts must be at least one metre (three feet) off the ground and the driving wheel must be made with soft material to prevent driver injury in case of accident.

The move comes after Kyoto-based Nintendo filed a lawsuit in February against MariCar, a Tokyo go-kart rental firm, for letting tourists wear unauthorized Nintendo character costumes.