Three people have been taken to hospital after being struck by a car near Lingfield Racecourse, police said.
Surrey Police was called shortly before 11pm on Saturday to reports a car had driven into pedestrians leaving an event.
The injuries are not considered to be life-threatening, no arrests have been made and the incident is not being treated as terror-related.
The Lingfield Park Resort hosted a concert from UB40 following Saturday’s racing.
Chief Inspector Dan Gutierrez said: “We would like to reassure the public that this incident is not believed to be terror-related.
“We know that there were thousands of people in attendance at this event and we are appealing to anyone who may have witnessed anything or have any dashcam footage of the lead up to the collision to get in contact with us.”
Anyone with information is asked to call police on 101 or Crimestoppers anonymously on 0800 555111.