Robbers armed with hammers and axes threatened staff and customers at a jewellery shop in Greater Manchester.
The gang targeted the watch counter at Prestons of Bolton in Deansgate in the town centre earlier.
Police said security features meant the robbers were locked in the store and had to smash their way out.
They stole Rolex watches.
The 150-year-old business is marketed as "the diamond centre of the north" and has been in Deansgate since 1913.
A BMW was seen leaving the scene of the robbery and was later found abandoned on St Georges Street.
Smoke from a security device filled the shop when staff raised the alarm.
None of the 15 workers in the store or customers were injured.
A haul of six valuable Rolex watches, believed to be worth more than £50,000, was taken in the raid.
