A gang of "brazen" bandits carried out a daylight smash-and-grab armed robbery at a Brent jewellers.
Eight men are believed to have rolled in on four mopeds armed with an axe and sledgehammer on Monday (September 7) afternoon.
The suspects smashed the windows and removed Indian and Iranian jewellery from the display, police said.
Officers were called to reports of a robbery in progress at a jewellery store on Kingsbury Road, at 2.12pm.
A number of brave shopkeepers and passers by confronted the thieves as they attempted to leave the scene, the Met said.
Detectives from the Met's Flying Squad are appealing for witnesses to come forward as well as anyone who may have taken video footage of the robbery in action.
Detective Inspector Scott Hartley said: "This was a brazen robbery carried out in the middle of the day.
"There were lots of passers by who would have seen the suspects smashing their way into the store and making off.
"I would like to praise the bravery of those in the local community who intervened in dangerous circumstances."
Two men were caught; one struggled and made off but another man was successfully detained by locals, officer said.
A 24-year-old man has been arrested by police on suspicion of armed robbery and was taken to a north London police station for questioning.
A sledgehammer was recovered by officers at the scene.
Witnesses and anyone with footage which could help investigating officers are urged to call the police on 020 8785 8655 or Crimestoppers anonymously on 0800-555-111.
Enquiries are ongoing and a police cordon remains in place at the scene of the robbery.
