Tokyo police requested Monday companies hosting go-kart city tours on public roads improve safety measures due to the increasing popularity of the attraction among foreign tourists.

The Metropolitan Police Department said it asked five go-kart rental companies in Tokyo to encourage patrons to wear helmets and protective gear while driving.

The activity is becoming increasingly popular among foreigners who are often seen driving go-karts around 2 meters in length and 1 meter in width around the streets of Tokyo. The tourists wear outfits reminiscent of Nintendo Co.'s game characters such as Super Mario while driving. A guided go-kart tour is typically available for between 6,000 yen ($54) and 8,000 yen for two hours.

The police said it also urged the companies not to allow drivers to use smartphones, something that is illegal when driving a normal vehicle, and to more thoroughly explain Japanese traffic rules to foreigners.

 Japan to strengthen safety steps for go-kart driving on public roads

The number of accidents involving go-karts has totaled 12 since police began tracking numbers at the end of March, of which foreigners were involved in 10.

In a March accident, for example, a woman from South Korea ran into a police box in Tokyo's Minato Ward after failing to take a turn at a crossing.

In accordance with the road traffic law, go-karts are designated as minicars, but under the law governing vehicle specifications, they are classified as mopeds. The vehicles with an engine capacity of 20-50cc, are equipped with indicators and headlights but the use of seat belts is not compulsory.

The Tokyo police also requested the companies reserve parking along the tour routes, and take other steps to deal with issues such as excessive noise.

Police are also considering measures to improve the visibility of the low-slung go-karts in collaboration with the transport ministry.

The police also sent a letter to the Tokyo Trucking Association to ask for their cooperation.

 Japan to strengthen safety steps for go-kart driving on public roads