Miniature motorcycles seized by police after they were ridden illegally are to be crushed in full view of the public.

A 40-tonne crushing machine will arrive on Shipley's Windhill estate on Monday to start the destruction.

By positioning the machine in an area notorious for illegal riding, police are hoping to send out a clear message to offenders and victims. Inspector Owen West, from Keighley Police, said: "We know we are reducing this problem and that levels are coming down, but the public perception is not there. By putting this crushing machine under people's noses in an area which has been badly affected by mini-bikes, we are hoping people will see that we are tacking the issue.

"The 40-tonne crusher will be brought in as an abnormal load. It's going to crush a number of bikes which have been involved with anti-social behaviour. The crushing process will be clear for everyone to see.

"We are told at every community forum we attend that it's a major issue and that people want action."

The crushing machine will be located on Holdsworth Street, just off Crag Road.

The initiative will be part of a high-profile crackdown on anti-social behaviour in Windhill.

Andy Rowley, chairman of Windhill Ward Tasking Team, said: "It's only a matter of time before someone is killed on one of these bikes because, if you are driving along, they are so small that you just can't see them."

The bikes have been ridden at high-speed on roads, pavements, parks, down alleyways and across people's gardens.

Officers can use powers under the Police Reform act to seize vehicles if they are causing annoyance or distress to the public. As part of the crack-down on miniature bikes, police are involved in a joint-operation with Trading Standards to give strong advice to shops which sell the bikes.

Insp West said some shops in the area were selling bikes which did not comply with British regulations. He said officers in the Windhill area were also targeting garages where petrol was sold to underage people. Last month, the Telegraph & Argus reported how a ground-breaking anti-bike squad had been set up to crack down on Bradford's motorcycle menaces. The Motorcycle Nuisance Group represents the most action taken against rogue bikers the district has ever seen.

Every report each agency receives is shared and stored so better decisions can be taken on how to deal with persistent offenders and biking hotspots. The group meets monthly to hear updates on the war against nuisance bikers and circulate photographs of regular offenders and their bikes. Although the off-road bikes are not illegal, there are no authorised sites in the district where they can legally be used.