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 threat level has been raised to critical by MI5's Counter-Terrorism Analysis Centre.
Sam Allardyce has quit as manager of Crystal Palace and retired from football management.
Authorities named Salman Abedi as the suspected attacker who detonated a bomb at the Manchester Arena.