The 18-year-old, from south London, was killed either inside or just outside Foot Locker store on London’s Oxford Street as hundreds of thousands of people descended on the Boxing Day sales.
Detectives said it was too early to establish a motive for the stabbing, although two groups of youngsters were said to have been involved in a confrontation. The victim’s body was found in the street at about 1:45pm.
News later emerged of a second stabbing nearby, close to the junction of Oxford Street and Regent Street, but it is not yet known if it was linked to the Foot Locker incident.
A vast crime scene was set up, from Duke Street to New Bond Street, near Bond Street Tube station. A forensics team erected a white tent in front of the Foot Locker, while a number of nearby shops were forced to close.
Detective Chief Inspector Mark Dunne said: “A number of weapons have been recovered from that scene. Whether I’ve got the murder weapon I don’t know. There’s an assortment of items, but no guns.”