The Governor of the US state of Missouri Jay Nixon has put the state Highway Patrol in charge of security in Ferguson, NBC News reports.
The St. Louis suburb has seen four nights of clashes between police and protesters following the fatal shooting of an unarmed black teenager by police.
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Witnesses reported hearing a "huge bang" at the venue during the concert on Monday evening.
ITV News travels to Britain's eastern-most city to gauge how the electorate will be casting its votes.
Carefully choreographed campaigns can become unstuck because voters have the power to peel back a politician's veneer.