A teenager who was bundled to the ground by passersby as he tried to escape with £20,000 has been jailed, along with his accomplice.

Mohammed Warsame, 19, was grabbed by onlookers and restrained by an off-duty police officer shortly after he tried to snatch a cash box from a security guard outside RBS in Thames Street, Kingston.

Barnes flying squad later swooped on his accomplice after he dumped his motorbike near Hampton Court Palace and clambered over a wall into the grounds of the estate.

Stevey Mackay, 19, was driving a stolen motorbike when he and Warsame carried out the attempted robbery on December 29, last year.

Police said Warsame had pulled the box out of the guard’s hands so hard he fell over.

On June 27, Mackay, of Queens Road, Thames Ditton, was found guilty by a jury at Kingston Crown Court of attempting to rob courier John Brooker and of stealing a Suzuki SV650 motorbike from Kingston earlier in the day.

He was sentenced to four years in prison by Kingston Crown Court on July 18.

Warsame, of Gloucester Road, Kingston, pleaded guilty to attempted robbery and being on the back of the stolen motorbike and was sentenced to three years in prison.

Judge Michael Hunter warned Mackay that due to his two previous convictions for robbery an indeterminate sentence could be considered.

The pair’s defence lawyer Melisa Mellin, said: “There is huge embarrassment for both these young men to find themselves in this court. For a good two years now these young men have distanced themselves from a criminal lifestyle.

“They know they have let themselves and their families down and are sorry to find themselves here.”

Detective Constable Marlon Pinto of Barnes flying squad said: “I would like to thank the guard, the public and an off-duty police officer who together detained Warsame at the scene.

“The quick reactions of police also resulted in Mackay being arrested nearby.”