Six men armed with axes have carried out a "smash-and-grab" raid at London's Selfridges department store.
Police said the robbers, reportedly dressed in burkas, smashed glass cabinets to steal high value watches.
Two suspects were later arrested when they came off a moped and members of the public stopped them fleeing.
The store in Oxford Street tweeted no-one was hurt in Thursday's robbery. The value of the stolen watches has yet to be established.
'Kicking and screaming'
Police said the men fled the shop on mopeds and motorbikes ridden by associates.
Matthew Carrozo said he heard a moped crashing just under a mile away from Selfridges and saw one man dressed in full motorcycle gear while a second man dressed in a burka fell on to the ground.
The 28-year-old, who was on the corner of Goodge Street and Charlotte Street, said he then saw a man run out from a nearby pizza restaurant and pin down one of the two people who were on the vehicle.
"Someone noticed a bag had fallen off the moped and that it had opened and a bunch a watches fell out," he said. "The duffle bag was full of watches and jewellery."
"The first guy pegged it down Charlotte Street and then he was held to the ground as other people were getting involved. He really put up a struggle.
"When cops turned up they put him in the back of a van and he was kicking and screaming," said Mr Carrozo.
Det Ch Insp Andy Noyes said: "I'd like to thank those members of the public who stepped in and detained our two suspects.
"Their quick thinking and brave actions have helped our investigation."
One of the arrested men remains in hospital with a fractured leg and the other is in police custody.
Sally Boazman, who was in Selfridges when the raid happened, said: "Suddenly I saw hundreds of people running to the door.
"It was a real panic situation."
DCI Noyes said: "This was a brazen robbery, and appears to have been well planned and thought through.
"Fortunately no-one was injured. The store was very busy and this will have been a shocking thing for people to witness."
The raid took place 30 minutes before the department store was due to close at 21:00 BST.