Police carried out a number of raids on the homes of suspected gang members today in response to "rising tensions" in the wake of the murder of a teenager on the UK's busiest shopping street.
Seydou Diarrassouba, 18, was killed after a fight broke out at a Foot Locker sports shoe store on London's Oxford Street on Boxing Day, described by police as "the busiest place in the United Kingdom on the busiest shopping day".
Eleven people arrested over the murder have been released on bail while officers today conducted a number of raids across the capital and made 13 further arrests.
These were for a range of offences including grievous bodily harm, robbery, affray, intent to supply drugs, burglary, forgery and handling stolen goods.
Met Police Commander Mak Chishty said: "We were aware of rising tensions in the wake of the murder and, having monitored the situation closely, including various comments that have been made on social networking sites, we felt it vital we take robust and prompt action in order to pre-empt any potential future violence."
The motive for the fight inside the shop remains unclear but Mr Chishty said there were a number of gangs present at the time.
He said police were aware of people wanting to "seek retaliation or revenge" for what had happened. "We don't want to see any other young person or anyone else lose their lives," he added.
Further raids are expected across the capital tonight.
He added: "This is just one of a series of measures we are carrying out in order to enhance the safety of the public and visitors to London, especially with New Year's Eve pending.
"We will continue to aggressively pursue any lawful opportunities against those who choose to become involved in violent crime and thus protect potential future victims, in line with the Commissioner's pledge on total policing."
Mr Diarrassouba, from Mitcham, south west London, died from a single stab wound which pierced his heart.
In a statement released through police today, his family said: "Our loving son and brother has been snatched away from us.
"A simple shopping trip has turned into a complete nightmare for our whole family.
"We are urging anyone who was in Oxford Street at the time of the incident to come forward with any evidence, no matter how little relevance they think it could have, to help the police with their ongoing investigation.
It added: "Whoever took his life took our backbone away.
"Seydou kept us upright and now we feel weak as we have lost a very special part of us.
"Life seems meaningless without our special son and brother.
"All we can say is 'Why?' He had so much consideration for others. We want Seydou to be remembered as the loving, down-to-earth, respectful and charismatic young man he was."
A Facebook page called R.I.P. Seydou has received dozens of tributes from friends of the victim and condemnation of youth violence.
A number of weapons were recovered at the scene and police have said they are particularly interested in obtaining videos of the fight shot on camera phones.
Another youth was stabbed on the same street just a few hours later.
The 11 people arrested earlier this week - 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.
Those arrested in today's raids, which took place at properties in Merton, Wandsworth, Southwark and Westminster, remain in custody at various London police stations.
Last year the Met Police launched Operation Connect to help support boroughs in cracking down on gang-related violence.
Officers have been identifying the most potentially harmful individuals, and then sending them "warning letters" offering the chance of help to exit the gang lifestyle.
If those selected refuse, they are subjected to a wide range of enforcement methods - including gang injunctions and being pursued for any suspected offences - to disrupt their networks.
It has resulted in more than 100 arrests so far in Waltham Forest and Haringey, along with tens of thousands of pounds of cash being seized and dozens of young people being diverted into more positive activities.
Anyone with information about either stabbing can contact police on 020 8721 4906 or Crimestoppers, anonymously, on 0800 555 111.