Police in Stirling are searching for a car that was used to try and pull over other vehicles while equipped with high visibility markings and flashing lights.
Officers said the Land Rover Discovery was seen driving dangerously on the A872 Stirling to Denny Road and on Nethermains Road in Denny.
The incident happened at around 5.40pm on Sunday.
Constable Neal Mealey, from Stirling Road Policing Unit, said: “We are particularly keen to speak with anyone who saw this vehicle in or around the particular areas mentioned.
“Additionally, if you believe that this vehicle attempted to stop you or other road users by means of flashing lights, then we would also encourage you to contact us.”
Anyone with information or dashcam footage can contact police on 101.