Undercover police snatch squads are dragging suspected moped thugs off their bikes in a radical new tactic to combat thieves and smash and grab raiders.

Teams of plain clothes officers are mounting ambushes on criminals using mopeds or scooters while they are caught in slow moving traffic as they ride into the West End.

They are deploying the snatch squads at traffic “pinch points” and strike when the moped riders are forced to come to a halt.

It comes amid a surge in moped crime, with 24 pedestrians targeted in a moped gang rampage across north London on Monday.

Four thieves on two mopeds robbed people of mobiles in Islington and Camden before police deployed a ‘stinger’ to trap one of the bikes in Islington.

Earlier the same day seven men on mopeds raided a luxury watch store in Fleet Street while brandishing a Samurai sword, bars and knives.

The “snatch and grab” tactic is being deployed by officers in Westminster as an alternative to the more risky policy of pursuing moped robbers at speed through the streets.

So far, two moped riders have been dragged off their machines by police.

One has been jailed for three years for robbery offences and another youth, aged just 14, has been charged with a series of moped enabled crimes.

A third youth was also tracked down later and arrested and charged.

The tactic is one of several new innovative methods being pursued by the Met to combat the scourge of moped robbers in London.

Police are using the “stinger” devices to deflate tyres and a forensic spray to mark individuals committing offences so they can be identified later.

The spray has been used more than eight times across London in recent weeks.

Detectives have been forced to adapt their tactics because of the risks of pursuing scooters at high speed through London’s crowded streets.

Fleeing suspects exploit strict police rules on pursuits by taking off their helmets so it becomes too dangerous to chase them.

Detective Superintendent Jess Ruddell, of Westminster Police, who has brought in the snatch squads, said: “This new tactic works and sends out a message that police are willing to do this and tackle these suspects.

“This is hugely manpower intensive but we are absolutely committed to getting on top of this offending. We are deploying covert and overt tactics to tackle these robberies.”

Sergeant Matt Carey, of the Operation Venice team which targets moped-enabled crime, explained how police deploy spotters to identify suspects travelling to commit crime in the West End.

They look for moped riders with pillion passengers who commit motoring offences such as jumping red lights or hiding licence plates with plastic bags.

Then the spotters radio ahead to the snatch squads lying in wait at ambush points where the traffic comes to a halt.

Sgt Carey said: ”The pinch points are where traffic slows down to a halt, where they have to walk their bikes through.

“They know they are at risk there but there is pretty much nothing they can do about it once they are boxed in by other vehicles.

“Once they are in that position this is where we jump out and remove them from their bikes. If the risk is too high and they are travelling at speed we will not do it.”

If moped criminals cannot be foiled at the scene, detectives use forensic techniques and CCTV to identify networks of individuals who are committing hundreds of offences across London.

Last month a moped robbery gang which committed more than 100 phone snatches in 18 days was jailed for five years after an investigation by the Westminster Crime Squad.

Claude Parkinson, 18, and two other youths aged 15 and 16 admitted conspiracy to rob at Southwark crown court.

Samsul Chowdhury, 40, of Bethnal Green got four years, ten months for handling stolen goods.

Police say the tactics are having an effect with the number of moped offences in Westminster now running at around 20 to 25 compared to around 100 a week a few months ago.

Det Supt Ruddell said: “We have seen a reduction but we are not taking our foot off the pedal.

“We want anyone thinking of coming into Westminster to commit offences to think twice because they are going to get caught.”

She added: “However, we cannot do this alone and I appeal to anyone who spots suspicious activity such as mopeds coming back to a lock-up in the early hours or youths congregating on bikes with pillions to contact us.

“These individuals are committing huge numbers of offences but there is a finite number of offenders who will be doing this.”

Detectives in Camden and Islington are appealing for help in tracing a moped gang who targeted pedestrians with phones on Monday.

A woman who was with a group of three or four friends on Essex Road just after 5pm was the first victim.

A witness said: “The woman was with friends and was making a call. The bike roared towards her, went through a red light and mounted the pavement. He didn’t even slow down as he snatched it, he knew what he was doing.

“The woman screamed and then looked dazed and was in total shock. It took them a fraction of a second. The bike was going over 50mph. Someone could have been killed.”

Two suspects ran off when the stinger was deployed against the moped in Islington.

Police are examining the bike for forensic clues to trace the pair.