A man suffered serious injuries when the quad bike he was riding overturned in Doncaster.
The 32-year-old was riding a red Polaris Predator along Hayfield Lane, Auckley, when he clipped a kerb close to the junction with First Avenue and the quad bike overturned.
He was taken to hospital with serious injuries, but South Yorkshire Police said they are not life threatening.
A 32-year-old man riding a second quad bike, a red Polaris Outlaw, remained at the scene to help officers with inquiries but the rider of a third bike left before police arrived.
Witnesses should call South Yorkshire Police on 101.