More than a million of extra police officers will be deployed in London and elsewhere . Thousands people are expected to attend the Three weeks ago Notting Hill Carnival . Police say intelligence indicates some gangs are planning to cause trouble . two-day , London was hit by outbreaks of rioting and looting .
Thousands of extra police officers will be deployed in west London and elsewhere . More than a million people are expected to attend the two-day Notting Hill Carnival . Police say intelligence indicates some gangs are planning to cause trouble . Three weeks ago , London was hit by outbreaks of rioting and looting .