A woman in her 20s is in a critical condition in hospital after a motorbike and car crashed in Lincolnshire.
The grey BMW 3 series estate and green Kawasaki collided on the B1168 New River Gate, in Holbeach, at about 17:00 GMT on Sunday.
The motorbike rider was treated at the scene before being taken to hospital.
Lincolnshire Police said it was concerned about the welfare of the car driver, who may have been injured in the crash but left the scene.
The force asked for help to trace the driver and for anyone who witnessed the crash to get in contact with officers.