Two people had to be cut free from a car after it collided with a tree in Diss in the early hours of Saturday morning.
The accident, attended by two fire crews from Diss, happened in Burston Road at about 2am.
A third person had freed themselves from the car before the fire service had arrived.
Three ambulances and an ambulance officer were called to the scene. All persons involved were taken to Norfolk and Norwich University Hospital.
Two were treated for head injuries, while another suffered a leg injury.