Armed raiders smashed through the doors of Selfridges in central London with a car before stealing designer handbags.
The four men threatened a security guard with a knife, and drove at a second guard in another vehicle as they fled the scene.
Nobody was injured in the raid at the luxury Oxford Street department store.
After stealing the high value handbags the gang were seen driving away north in a white VW Golf, before heading into Wigmore Street.
Selfridges said the store is continuing to trade as normal following the raid, which happened shortly before 04:15 GMT.
Det Con Tom Aylward said it had "lasted a matter of minutes".
"I'd like to appeal for those who may have been in the area at the time... to get in touch with police," he said.
No arrests have been made.