A quarter of London's gangs are based in Lambeth, a council report to be published tomorrow shows.

Research undertaken for Lambeth Council found 40 gangs were operating in the borough, with one believed to include as many as 2,500 members.

The council is hosting a gang summit tomorrow (Thursday) to hammer out a plan to take on the problem.

The report found some young people joined gangs for fun and companionship while others signed up through fear and coercion.

Most of the gangs were based in poorer areas including the Tulse Hill Estates.