Gordon Brown declared tonight that new anti-knife crime measures will be announced next week after four men were stabbed to death in separate attacks across London in just 24 hours.

The Prime Minister said the latest spate of murders was “shocking and tragic” a few hours after the Commissioner of the Metropolitan Police issued a rare appeal for calm in the capital.

Jacqui Smith, the Home Secretary, will set out the Government’s latest initiative on Monday. Later in the week, the first ever cross-government youth crime plan will be published with new enforcement and sentencing measures. It will also include a new approach to youth crime prevention, including “tough parenting” programmes.

Mr Brown said this evening: “The terrible stabbings that have occurred this week are shocking and tragic, and my thoughts are with the families and friends of those who have been hurt or killed in these attacks.”

One of those who died was just 19 years old, the 20th teenager to die violently in the capital so far this year. Another was a 20-year-old who bled to death after being stabbed in what appeared to be a road rage incident.

Elsewhere yesterday a man was killed in a knife attack in West Bromwich, bringing the national death toll on a single day to at least five.

But it is the spate of knife crime among youth gangs in London that has been most shocking, piling pressure for action on police and political leaders.

Sir Ian Blair, the Met Commissioner, said today: "There has been a tragic death toll from knife crime in London over a 24-hour period. Four men have been killed - one a teenager - and a fifth remains critically ill. Each is an absolute tragedy and my thoughts are with the families and friends of the victims.

"These attacks are not connected nor do they all involve teenagers. Detectives have made arrests in three of the four murders. I want to reassure the public that the MPS is doing everything possible both in terms of thoroughly investigating each case and in continuing to carry out proactive operations to get knives off the streets.

"The dreadful loss of life in just 24 hours graphically illustrates the need for everyone to pull together to put an end to this unacceptable violence."

Two people have been arrested over the death of the teenager, who was knifed in a confrontation at a bedsit in Gloucester Road in Edmonton, North London. Officers were called to reports of a fight at the address close to Silver Street railway station at about 2.30pm yesterday.

Paramedics were called and the victim, who had suffered multiple stab wounds, was taken to the North Middlesex Hospital where he later died.

A Metropolitan Police spokeswoman said a 26-year-old woman and 34-year-old man were arrested in connection with the attack.

In Walthamstow, northeast London, a man aged in his 20s was also fatally stabbed. Police found the victim with stab wounds to the head and chest shortly after 8.30pm last night.

Paramedics fought to save his life at the scene but he was pronounced dead about an hour later.

In Tottenham, North London, a murder inquiry was launched after a man was found stabbed to death at the rear of a disused pub in Tottenham High Road yesterday morning. The victim, thought to be in his 40s, was suffering from head injuries and slash wounds. He died at the scene.

Four people remain in custody after a 20-year-old man was fatally stabbed in Leyton, East London in what was reported to be a road rage attack.

It was reported today that Adnan Patel was knifed in the stomach after a dispute with a number of men in a white van. He had tried to escape in his Ford Focus but lost control and smashed into a car a few streets away. "Residents tried to save his life as he lay whispering prayers," one newspaper reported.

In West Bromwich, a man died after he was stabbed during a row in the street, police said today. The 20-year-old victim, who has not yet been named, had been involved in an argument with another man in Bustleholme Avenue, Charlemont Farm, before he was killed.

A 21-year-old man has been arrested on suspicion of murder and a woman of the same age has been arrested in connection with the stabbing, which happened at 11pm yesterday.

Meanwhile, the new Mayor of London, Boris Johnson, issued a statement regretting the death of the four Londoners and calling for a co-ordinated response to the knife-crime crisis.

“We need to do all we can to address the long term complex root causes of violence as well as ensuring the police are providing an effective deterrent to those who carry knives and guns," he said.

“We are in this together and we all need to take responsibility. That’s why we are talking to the Government about bringing forward new measures next week that will help to address the underlying causes of knife violence."

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