The bikes were confiscated after being ridden illegally

The bikes had been seized over the past year after their riders committed drink-driving offences or displayed anti-social behaviour.

Police said such bikes, which can reach speeds of up to 50mph (80km/h), had led to scores of complaints.

Riding groups are trying to discourage people from using the bikes illegally.

It's the fun of being on something so small and yet so powerful Rob Davies, mini-moto enthusiast

The bikes were crushed at Devon and Cornwall Police headquarters in Exeter on Tuesday.

They were confiscated after being ridden illegally on public roads or in parks.

Police said many people did not realise the bikes were subject to traffic laws.

Devon and Cornwall Police said: "The rider must have a driving licence, tax, insurance and a helmet."

Officers have now started a campaign against irresponsible use.

Insp Richard Pryce of Devon and Cornwall Police said: "They can cause incredible disturbance to communities. They make a huge amount of noise, and can be very lethal and very antisocial."

Responsible riders said they were safe if used properly.

'Wrong hands'

Enthusiast Rob Davies said: "It's the fun of being on something so small and yet so powerful, riding them on tracks and circuits.

"They also don't hurt anywhere near as much as the big bikes do when you fall off because they are so low to the ground."

The South West Mini Moto Club said it wanted to encourage riders to join a responsible group so they could use their bikes at organised tracks legally.

Devon and Cornwall Police warned they would continue to use powers to crush any mini-motos found being ridden illegally or irresponsibly.