Eleven people arrested over the murder of a teenager stabbed to death on the UK's busiest shopping street on Boxing Day have been released on bail.
Seydou Diarrassouba, 18, was killed after a fight broke out at a Foot Locker sports shoe store on London's Oxford Street, which police described as "the busiest place in the United Kingdom on the busiest shopping day". Another youth was stabbed on the same street just a few hours later.
All those arrested - two 22-year-olds, five 19-year-olds, three 17-year-olds and one 16-year-old - have been bailed to dates in mid-January, Scotland Yard said.
A post-mortem examination conducted at Westminster Mortuary determined that Mr Diarrassouba, from Mitcham, south west London, died from a single stab wound which pierced his heart.
The motive for the fight inside the shop remains unclear. Police said they were particularly interested in obtaining videos of the incident shot on camera phones.
Detective Superintendent John Sweeney said: "Our sympathy goes to the family of the victim at this time and we are appealing for witnesses to come forward.
"We know there were a number of people filming the incident inside Foot Locker and may have captured the incident or its aftermath and we are appealing for these people to contact us."
Schoolfriend Munawar Shaikh, 20, described the dead youth as a "big personality" who always had a smile on his face. The pair grew up together and attended Rutlish School at the same time.
Mr Shaikh said: "I heard about it on social network sites. It's devastating. I had lost contact with Seydou but he was such a big personality and a person everyone in Mitcham would know.
"He was just a good kid who always had a smile on his face."
A Facebook page called R.I.P. Seydou hosted dozens of tributes from friends of the victim and condemnation of youth violence.
Just hours after Mr Diarrassouba was killed, a 21-year-old man was stabbed in the thigh at the junction of Oxford Street and Regent Street.
The Metropolitan Police also denied a Taser electroshock weapon was deployed by an officer in the aftermath of the attack on Mr Diarrassouba after footage emerged on YouTube of tension between police and the crowd at the crime scene.
Commander Steve Rodhouse said: "Officers can be seen in the footage pushing the crowd back and one officer is shown to remove his Taser from its holster, although at no time was it ever deployed.
"Clearly in those initial early stages, officers would have been unaware of what had occurred and where the suspect(s) might be and their priority would have been to prevent further injury or loss of life to those in the area."
Witnesses to the stabbings can contact police at the incident room on 020 8721 4906 or Crimestoppers on 0800 555 111.