Politicians, youth leaders and those affected by violence have been meeting at a conference in London aimed at tackling gang culture.
As Liz Wickham found, it's thought the arrest of more than 200 gang leaders in the wake of the 2011 riots may have created a power vacuum, in which younger gang members have grabbed power, on a wave of violence:
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The 34-year-old from Coulsdon in Surrey died during the private party in Headley in the early hours of Monday, Surrey Police said.
The Home Office made the arrests at various restaurants across London on July 4.
Mayor of Newham Sir Robin Wales criticised the International Olympic Committee on the fourth anniversary of the opening ceremony.