A gang of sledgehammer and machete-wielding robbers are facing jail after smashing their way into a string of jewellers including a store in Orpington.

The raiders struck at seven jeweller and money transfer shops in London and Manchester over a year, making off with £500,000 in cash, expensive watches and jewellery.

Disguised in helmets and gloves, they used concrete blocks and hammers to shatter window displays and glass cabinets and threatened staff with knives and machetes before fleeing on stolen scooters.

On January 13 this year, the gang wielded concrete and a sledgehammer to snatch £37,448 of jewellery and watches from a jeweller's in Crofton Road.

Video footage shows one gang member smashing the shop front with a hammer and stealing jewellery from inside as another, armed with a machete, keeps watch.

One of the robbers was caught when City workers and a plain-clothes police officer blocked his escape after a raid at Carrs Jewellers in London’s Liverpool Street on January 22, which was captured in mobile phone footage by a passerby.

Alex Parle, who is 6ft 7in tall, was caught after he struggled to climb onto the back of one of the mopeds driven by his accomplices Conor Gartland, 18, and Thomas O'Connor, 23, during the getaway.

A shop manager tackled Parle, 22, from Surrey Quays, as he ran after the scooters but he produced a machete and swung it at people before running off.

News Shopper:

An image released by City of London Police of a shop manager tackling one of the robbers in Liverpool Street

He was later arrested.

Parle, O'Connor, also from Surrey Quays, and Gartland, from Bankside, pleaded guilty at the Old Bailey to plotting to commit robbery between February 15 last year and January 23 this year.

The trio also carried out robberies in Peckham, Stratford, Tower Hamlets, Manchester and the Walworth Road area of south-east London.

They will be sentenced by Judge Wendy Joseph QC on December 15 at the Old Bailey.

The Flying Squad, City of London police and Manchester police joined forces to catch the robbers, who were part of a wider organised crime group.

O’Connor, alongside Gary O’Brien, 22, Jamie Hull, 21, both from Southwark, Michael Ogun, from Enfield, and a 17-year-old, who can not be named for legal reasons, were also convicted of conspiracy to rob a jewellers in Tower Hill, following a separate trial at Woolwich Crown Court.

They will be sentenced on November 20.