The force was called to Market Square at 3.18pm yesterday after reports that a vehicle had collided with a police officer.
The vehicle failed to stop following the collision with the officer, who was on-duty at the time of the incident.
The officer has been taken to hospital with head injuries. He was discharged from hospital last night.
Investigating officer, Detective Inspector James Mather of Force CID, said: “I am appealing to anyone who may have information about the incident to please contact police immediately.
“I would particularly like to speak to anyone who has mobile phone or dashcam footage of the incident or the vehicle being driven in the town to come forward.
“The vehicle, a red Vauxhall Astra, was involved in a number of road traffic collisions after the incident in Market Square, but thankfully no-one was injured during these subsequent collisions. I would also like to hear from anyone who saw a vehicle matching the description being driven erratically in the town.
“The vehicle was later located in Osier Way but there was no driver or passengers in the car. We believe the driver and two passengers, all believed to be male, fled the scene.
“Thankfully the officer is now recovering at home with support from his family and the force. This incident highlights the sacrifices that police officers and staff make every day to protect the public across the country.
“Anyone who has any information about the incident is urged to call police on 101 and quote reference number 747 (13/2).”
