A stark warning for dirt bike riders -- after Police impounded a number of vehicles in Auckland this week

Eight bikes were seized in three separate events in the Counties Manukau area.

In one, a man has hospitalised after running through a red-light in Otara, without a helmet on, and crashing into a vehicle.

Police aren't ruling out charges.

Other instances involve stolen bikes, riders ripping up turf at parks, and more people riding without helmets.

Inspector Kay Lane says in general, these riders show little regard for safety and it's only a matter of time before someone's killed.