An urgent review of police tactics to combat London’s wave of violence was launched by politicians today as six more people were stabbed in the capital.

The London Assembly’s Police and Crime Committee said it wanted answers about why the increase in violence was happening and “why policing tactics are failing and what can be done to keep Londoners safe”.

The committee said it would examine the Mayor’s knife crime strategy, including the effectiveness of social media and advertising campaigns and the knife detection wands being offered to schools in London.

Details of the review comes after a 44 per cent surge in murders in London, with the Met revealing there were at least six more stabbings last night.

Four teenage boys were among those knifed in separate attacks across the city:

Two teenagers, aged 16 and 18, were stabbed just after 3pm in the Nightingale Estate in Hackney;

Another boy, also 16, suffered stab wounds in his arm after an altercation on The Embankment in Twickenham;

At 5pm, police were called to Beresford Square in Woolwich where an 18-year-old man was stabbed in the leg in a fight. A man was arrested on suspicion of possession of an offensive weapon and taken to a south London police station, where he remains in custody;

A man aged 27 was stabbed outside West Croydon railway station at 6pm;

A 21-year-old man was stabbed in a doorstep burglary at his home in Greenwich at around 11.30pm;

None of those attacked are believed to be seriously injured.

Witnesses to the Hackney attack said a 16-year-old boy was dragged from a moped and set upon by up to eight youths said to be armed with machetes.

One resident said: “The boy was on a moped was going around the park and he got jumped by another group.

“They pulled him off the moped and it went from there. There were seven or eight guys around the boy on the floor. They had these long machetes.

“I came out of my flat and shouted ‘stop it’. They stood still and dropped the machetes to their sides. I think I may have saved his life.”

Police said officers found an 18-year-old man a short distance away suffering from a serious leg injury. He was also taken to hospital for treatment.

Today Tory London Assembly member Steve O’Connell, chairman of the Police and Crime Committee, said: “The Mayor and the Met need to take hold of the situation. We are determined to find out what is working and what is not.”

He added: “Enough is enough. Where is the evidence that the Mayor’s new taskforce is working? Did the Met take its eye off the ball on gun-related crime? Londoners deserve urgent answers.

“We need to unite and say this senseless killing must stop. We cannot have a summer of violence and bloodshed. The Mayor and the Met need to prove they can stop this surge.”

He questioned poster campaigns’ effectiveness, saying : “Violent criminals don’t watch adverts from the Mayor about knife crime. Many young people now live in a culture of fear and feel at risk. They want more than an ad campaign, they want to know concrete steps are being taken to protect them.”

A spokesperson for the Mayor of London said keeping Londoners safe was his top priority but said London’s police service was “overstretched and under-resourced.”

She said : “ Violent crime has been rising across the country since 2014 and the Government is failing in their basic duty to keep people safe – imposing cuts of £1 billion on the Met Police which risk sending police numbers to historically low levels. The Home Office’s own evidence shows you cannot keep cutting without consequences, and violent crime devastates communities and ruins lives.

“The Mayor is doing all he can to compensate for the failure of ministers. City Hall is investing an extra £110 million in the Met to keep police numbers as high as possible, and has also set up a new £45 million Young Londoners Fund to help tackle the causes of violent crime and support young people to turn away from criminality.

"Sadiq refuses to accept that nothing can be done to stem the appalling tide of violent killings we are seeing on our streets and together with the police, community groups, victims and their families and Londoners, will continue to work ceaselessly to tackle violent crime.”