Two cyclists on one bicycle circled an intersection while the passenger sprayed fire extinguisher foam into the air in Tottori Prefecture on June 7.

Laughter and cheers can be heard from onlookers gathered nearby. A witness who was at the scene described the atmosphere.

Witness / Even when police tried to step in, people were shouting things like 'Go for it!' and 'Do it again!' The excitement just kept building.

The situation quickly spiraled out of control. Moments later, the bicycle was being pursued by an unmarked police vehicle.

Shortly afterward, it collided with a passenger car. The teenage boy riding on the back of the bicycle suffered critical injuries and remains unconscious.

Police say the person operating the bicycle fled the scene following the crash.

Authorities have not disclosed the driver's whereabouts, saying the matter remains under investigation.

Police are continuing to examine the circumstances that led to the incident.