The number of homicides in London so far in 2018 is the highest in a calendar year this decade as mayor Sadiq Khan has been told “drastic action” is needed on violent crime in the capital.

Jay Sewell was the victim of the latest violent death in the capital when he was stabbed to death in a fight in Lee, south east London, shortly before 10pm on Tuesday.

The death of the 18-year-old brings the grim tally of violent deaths in the capital this year to 125, the largest number in a calendar year since 2009 when there were 131.

It comes as Mr Khan’s plans for a violence reduction unit (VRU), which would see health, police and local government focus on young people, poverty and social alienation to cut the risk of children getting involved in crime, require more detail, according to London Assembly members.

(PA Graphics)(PA Graphics)

The unit, which has been given initial funding of £500,000, is modelled on a similar scheme in Scotland, but members of the London Assembly Police and Crime Committee have said Mr Khan needs to take “further and drastic action” to reduce violence.

In a letter to Mr Khan, committee members said: “We are concerned that the narrative around the VRU may give some Londoners the impression that it is set up and taking action, when in fact it is very much in the early stages of development.”

They claim the VRU’s funding from surplus business rates is “far from sufficient to resource the unit over the long term”, and called for a move away from the focus on young people, knife crime and gangs.

Members want the unit to tackle a broad range of violence and the particular issue of adverse childhood experiences.

A spokesman for Mr Khan said he was “leading from the front” and that it was “clear there is no one single solution to tackling this complex issue”.

(PA Graphics)(PA Graphics)

Meanwhile, Scotland Yard said six people are in custody on suspicion of Mr Sewell’s murder, including a 16-year-old boy taken into custody following a raid on a property in Avery Hill on Wednesday afternoon.

Three men aged 22, 31 and 56 and two women aged 29 and 53 have also been arrested and taken to police stations in south London for questioning.

Detective Chief Inspector Simon Harding said: “We are at the very early stages of our investigation into this tragic murder.

“We urgently need to hear from anyone who saw what happened in Alwold Crescent.

“We have already spoken to a number of people as part of our initial inquiries, but we would like to hear from anyone who lives near the scene who saw anything that might assist our investigation to contact us.

“Did you see either group going to and from the scene? Did you see the fight?

“Perhaps you saw something after the incident that in retrospect may be linked.

“We would urge you to get in touch right away.”

In 2018 there have been 72 deaths involving a knife, 13 involving a gun, one involving a knife and a gun and one a crossbow.

Just over a third of victims, 44, were aged 16 to 24, of whom 10 were shot, 32 were stabbed and one was killed in an attack involving a knife and gun.

Twenty-five of the victims were aged 19 and under, six of whom were shot and 16 of whom were stabbed.

Earlier this month Metropolitan Police Commissioner Cressida Dick insisted the tide was turning against knife and gun offences, although she admitted it would take time to tackle the 180 violent gangs in London who drag children into crime.