Moped gangs terrorize London in about 50,000 crimes per year, police say Police say the vehicles make it easy to smash and grab from victims.

 -- Mobile gangs using mostly stolen mopeds and scooters have been terrorizing London, committing robberies and attacks on people walking along city streets, police say.

London’s Metropolitan police say that up to 50,000 crimes have been committed a year by mobs on these vehicles; about 1,500 mopeds or scooters are stolen and 2,500 thefts carried out on them every month.

“This is becoming out of control in London and it is spreading to other towns,” Ken Marsh of the Metropolitan Police Federation told Sky News.

The two-wheeled vehicles are agile and enable criminals to easily smash and grab items from victims. Many times, they mount sidewalks to grab items from pedestrians, then make quick getaways.

Police say the crimes are two-fold: Scooters are stolen and then used to commit crimes. The vehicles are often stolen from areas of Outer London and used to commit robberies in the affluent Central London neighborhoods.

The dangers posed by these gangs coming in close contact with the public has made it difficult for the police to chase them.

“These pursuits are very dangerous, these bikes can go at very fast speeds -- 30, 40, 50 miles per hour around public members so they can mount the footways, down alleyways," Marsh said. "They have no interest in who they harm or endanger or if they have committed a crime -- and my colleagues have to make split decisions. Do I follow that person? Do I pursue them in the same manner? You know, this is very, very quick time that they have to decide and act upon it and things can go wrong.”

Marsh said stronger legislation with more severe penalties is needed to help deter the crimes.

The police said they are employing new tactics to defeat this latest crime wave. They include using remote control spikes, DNA-tagging sprays and slimmer police motorcycles.