The incident happened at about 7.20pm last night (June 19) in Badminton Road outside the Dog Inn pub, when a motorbike collided with a car.
Both the motorcyclist and pillion passenger received substantial injuries, although they are not believed to be life threatening.
Enquiries are ongoing into the cause of the collision and police are keen to locate a dark blue Citroen estate motor car which may have sustained damage to the rear and is missing its rear bumper.
If you have any information regarding the collision, the location of any such vehicle or who may have been driving it at the time, contact Avon and Somerset police on 101.
Call the charity Crimestoppers anonymously on 0800 555 111 or via www.crimestoppers-uk.org.