A teenage boy has died after falling from a moving van in South Yorkshire.
The 15-year-old was standing on the tow bar of a Renault Traffic van being driven on Third Avenue in Woodlands, Doncaster, at about 1800 BST on Sunday.
He fell from the vehicle, hit his head on the kerb, and later died in Doncaster Royal Infirmary of serious head injuries.
Police appealed for witnesses to contact them and urged young people not to hang on to moving traffic.
Sgt Andy Noble, of South Yorkshire Police, said this was not the first time he had seen an incident of this kind, but added he was not aware of "traffic surfing" - a recent craze where people climb on top of or hang on to the back of moving vehicles, sometimes on skateboards.
"It's something I've seen before, but that was in Barnsley and not round here," Sgt Noble said.
"It is the first time I've heard the phraseology 'traffic surfing' but that's not to say that's not what's happening, it could be that it's happening and people are getting away with it without anyone getting hurt."
Sgt Noble said it was not yet known if the 18-year-old van driver knew the boy was hanging on to the back of the vehicle.
He was not injured and is helping police with their investigation.
"Whether it was with the driver's knowledge or without, the fact that the young lad has taken hold of the vehicle has resulted in his death," Sgt Noble said.
"Yesterday it was him, tomorrow it could be someone else. We can't say enough not to do this."