Police have warned that children are putting themselves at risk by riding motorised skateboards at speeds up to 20mph on roads and pavements across the district.

Some go-peds, which can either be electrically or mechanically-propelled, should not be ridden in public places.

Others can be classed as motor vehicles meaning riders need to wear a crash helmet and have a licence and insurance.

But police say some back street dealers are selling the new craze to parents without any warning of the legal requirements.

And children as young as 12 have been riding them in roads and on paths, prompting complaints from worried members of the public.

Community safety sergeant Paul Hepworth, of Bradford North Police, said: "These go-peds can travel at anything from 5mph to 15-20mph, depending on the model.

"They are being ridden by youngsters on pavements and roads all over the district. They could have all sorts of accidents at those sort of speeds.

"There have been a number of complaints about the way they are being ridden from people who are principally concerned for the safety of the children.

"We are concerned for their welfare and well-being and the likelihood of them having an accident. Parents also need to be aware of the legal restrictions on using them on the roads."

Sgt Hepworth said it was a case of young people having fun.

But he added: "We are concerned about it. The mechanically-propelled ones with an engine make a noise, are a nuisance and are dangerous.

"Youngsters of 12, 13 and 14 stand or sit on them and they are being ridden all over the place but they can be classed as a motor vehicle. Reputable dealers are selling them with the proper warnings but there are back street dealers who give no indication to parents of the legal requirements."