The 15 London wards with the most criminals

Police say each one contains hundreds of offenders, including a hard core of serious criminals responsible for luring others into their world - sometimes over several generations.

Four of the wards are in Greenwich, three are in Lewisham, while Lambeth, Newham and Tower Hamlets each have two and Haringey and Southwark have one each.

They were identified by analysing convicts' home addresses.

Police believe the high concentration of criminals in these areas is increasing the chances of convicts reoffending.

They plan to monitor and assist people released from prison with the aim of preventing them falling back into crime, beginning in Newham, Lambeth and Lewisham.

Teams of police, probation officers, council staff and specialists in areas such as drugs, alcohol and housing will help ex-convicts find a job or housing or get treatment for addictions.

Repeat offenders will be targeted to ensure they comply with court orders or conditions of release, and police will act against those who fail to do so.

Another objective will be to stop the most serious convicts committing new offences and drawing others into crime by acting as recruiting sergeants.

The Diamond initiative is modelled on the Million Dollar Blocks approach used in America, so called because of the cost of keeping large numbers of residents from single streets in prison.

It is backed by Boris Johnson, the Government and the London Criminal Justice Board. The Mayor said: "This scheme to break the cycle of reoffending will not only give offenders the help and support they need, but also involve communities in practical solutions to tackle crime and make them feel safer."

Home Secretary Jacqui Smith said Diamond could help reduce crime in the capital significantly. She said: "It will mean increased support and supervision of offenders, with resources targeted on neighbourhoods with the greatest need, backed up by swift enforcement measures with the aim of making these communities safer for everyone."

The scheme will initially target offenders in the Evelyn, New Cross, Coldharbour and Canning Town North wards.