A double killing in Tottenham could also be linked to the cycle of black-on-black violence.

The BBC's Tim Donovan: "There is an emerging picture of gang violence in this area, probably gang-related"

The latest fatal shooting took place in broad daylight in Harlesden, north west London, on Monday.

The victim, who has not been named yet, was chased by a gang of up to five men, shot down and then "finished off" at close range.

The killers, who were all black and in their 20s, sped off in a blue car.

The victim, who was in his late 20s, was gunned down outside a block of flats in St Mary's Road, Harlesden, at 1509 BST.

'Police arrived within three minutes'

A member of the public rang 999 and police arrived on the scene within three minutes.

An air ambulance was called to the scene but paramedics pronounced the man dead at 1528 BST.

A Metropolitan Police spokeswoman said: "There have been no arrests and inquiries continue. The incident is being treated as murder."

Detective Chief Inspector Julian Headon, who is heading the inquiry, said the victim was shot at several times as he walked along the street.

DCI Headon: "The young man was shot dead when he fell over"

He said: "He was approached by people in a vehicle, who got out, shot at him and chased him down the road.

"Ultimately, when he had fallen over, they shot him dead in the street."

Scotland Yard said it was too early to link the shooting with two other murders last month.

Police are examining links between the murder and an attack on two men in their car in Acton, west London, on 28 May.

Nightclub shooting

Nine shots were fired, killing 25-year-old Clayton King and seriously injuring another man.

That shooting came hours after the murder of Adrian Roberts, 23, in an ex-offenders' hostel in Harlesden.

Police question potential witnesses to the latest murder

In early May, seven people were wounded at a nightclub in east London when two men fired at each other.

Scotland Yard said they were keeping an open mind about the cause of the violence but rivalry between dealers in crack cocaine, some of them Jamaican-based, could be to blame.

It is also possible that a couple murdered in front of their seven-year-old daughter were victims of the same feud.

Patrick Smith, 33, and his partner Laverne Forbes, 28, were shot dead at their flat in Tottenham in north London on 25 May.

The couple's seven-year-old daughter was treated for shock and is now being looked after by relatives.