A band of thieves smashed their way into a royal jewellers in central London on Monday evening, making off on mopeds with a valuable haul, police said.
The gang used weapons including an axe and bats to break into Mappin and Webb jewellers on Regent Street, in the heart of London's shopping district.
A trio of thieves stole "a high value of jewellery items" while three accomplices "waited outside on revved-up scooters throughout the raid", London's Metropolitan Police said in a statement.
The force did not give a figure for total losses at Mappin and Webb, where numerous pieces of jewellery run into the tens of thousands of pounds (dollars, euros).
The high-end store has been a supplier to the British royal family for more than a century and the company's master craftsman is the custodian of the Crown Jewels in the Tower of London.
After the raid the mopeds sped off in separate directions, with one racing towards Oxford Street before crashing into a female pedestrian who was not seriously injured.
"We know that the group panicked and rode recklessly in different directions to escape," said Matt Hollands from the Metropolitan Police.
"I'd like to appeal for those who saw the individuals involved, either at the scene or fleeing, to get in touch with police and send us any images and footage that they have," he added.
One weapon and two of the scooters abandoned after the heist have been seized by police, but so far there have been no arrests.