A manhunt is underway and the public have been warned to be on their guard after a lone knifeman stabbed four lone people within 15 hours within a quarter of a mile radius.

The knifeman described as a tall, skinny, black man wearing a hood and dark clothing approached all of the people from behind in what police said was random attacks and not linked to terrorism.

He first struck stabbing a woman aged 45 in the back near the busy North Circular in Edmonton yesterday evening around 7pm.

He struck again just after midnight less than a quarter of a mile away stabbing a man repeatedly in Park Avenue.

Enfield Independent:

Police in Aberdeen Street - the scene of the first stabbing

Enfield Independent:

Police in Aberdeen Street

A third man, 23, was knifed near Silver Street station and his latest victim was stabbed a few streets away from his second victim.

Enfield Independent: Enfield Independent:

Police in Fore Street

The fourth victim was seen lying face down on the floor with a "gaping hole in his back" by residents this morning.

A man who dialled 999 said he heard the victim, an Asian man speaking Bengali on the phone, after he was stabbed in the side of his back in broad daylight.

An air ambulance was seen leaving the main road which runs alongside the estate and forensic officers took photographs around where the man was stabbed in Folkstone Road.

A 50-year-old hospital worker and PHD graduate said he was in his kitchen at 9.30am when he heard somebody shouting "oh my God."

The resident said: "I was watching TV and I heard from outside my kitchen somebody shouting 'oh my God, oh my God.

"The sound was moving around the front of the estate from the back and I called 999.

"When I came out, his attacker was gone and I heard the man speaking on the phone saying "why didn't you come yet?' "He was speaking Bengali - I thought perhaps he was on the phone to his family or trying to get help.

"I saw when police cut his clothes off his back there was a gaping hole in the side of his back.

"There was blood all around him, it was like a bloodbath.

"It was horrifying. My son was inside, he is only 15 and he has been left traumatised. He said in that moment 'dad please can we leave this place.' "I came out onto the main road and he was on the floor face down and then within a minute, the police arrived. They were excellent.

"The ambulance came four or five minutes later."

Enfield Independent:

Fore Street

The resident said the estate is known for having gangs of between 15 and 20 men "hanging around in the car park day and night."

He added: "This area is getting worse and worse. Every day people are gathering in the car park screaming - it is common here.

"After 4 o'clock when the schools finish school, they are all here - Romanians, black men, people of all ages."

While a man, the second victim, was caught on CCTV limping down Park Avenue at around midnight, during the stabbing spree.

A local cafe owner said police called into his cafe this morning to check the CCTV which looks into Park Avenue.

The 50-year-old, from Enfield in north London, said: "It has all gone crazy.

"Last night there was a guy walking down here with a limp followed by a couple of others.

"I heard somebody was attacked at the end of Park Avenue and police turned up at around midnight.

"Police came in the cafe this morning and while we were looking at the CCTV, something kicked off off across the road at the estate and he had to go and deal with that.

"Police said it is all linked. They said they believe somewhere between 11.30pm and 00.30am something happened at the other end of Park Avenue."

Enfield Independent:

Fore Street

One man was arrested this morning on suspicion of GBH and is in police custody.

A second arrest has also since been made by investigating officers.

A man aged in his 40s was arrested at a residential address in Edmonton on suspicion of GBH and taken into custody at a north London police station.

Scotland Yard said: "Detectives are appealing for information and urging the public to stay vigilant following a series of stabbings in the Edmonton area.

"Urgent enquiries are underway to trace the single male suspect who is described as a black man, approximately 6ft 3ins tall, of skinny build and wearing dark clothing, possibly a hooded top.

"There is a lot of police activity underway to catch this suspect.

"Extra resources have been called upon and are on the streets now working to keep the public safe and catch the individual responsible.

"The first stabbing took place at 7.02pm on Saturday at Aberdeen Road following reports of an assault. London Ambulance Service also attended. The victim, aged in her 45, had sustained a stab wound to her back after being attacked by the man.

"She has been taken to an east London hospital where she remains in a critical condition.

"The second incident took place four hours later at approximately 0.15am on Sunday, to reports of a male suffering stab injuries in Park Avenue.

"Officers and London Ambulance Service attended and the male victim was taken to an east London hospital for treatment. His condition is not life threatening.

"The third incident on Sunday at 3.55am police were called to Seven Sisters tube station to reports of a man stabbed. A 23-year-old man suffered stab injuries.

"He remains in hospital in a stable condition. Initial enquiries have established that the man may have sustained his injuries in Silver Street, Edmonton.

"The last incident took place at 9.43am in Brettenham Road. Officers attended and found a man with a stab injury to the back.

"He has also been taken to hospital for an assessment of his injury. His injuries are not life threatening but potentially life- changing."

A/DCI Stuart Smillie from North Area Command said: “We are doing everything we can to apprehend the suspect behind these cowardly and senseless attacks.

“The four stabbing related incidents are being treated as potentially linked. The four victims are from different backgrounds and appear to have been selected at random due to them being alone and vulnerable. There is nothing to suggest this incident is terror related.

“We are working on the hypothesis that the single male suspect is acting alone and mental health issues may be a factor. All of the people he has targeted have been walking alone and the suspect has approached from behind without warning.

"The motive from the stabbing appears to be solely to inflict harm. Early accounts suggest none of the victims were robbed or engaged in conversation before they were attacked.

“My advice to the public in the area where these incidents took place stay vigilant, beware of your surroundings and call 999 if you see anyone matching the suspect's description behaving suspiciously.

“His description has been circulated to all officers in North Area who are carrying out patrols, CCTV footage enquiries and policing busy areas around where the incidents took place, particularly where he was last seen where police arrived four minutes after the call to police was made.

"A picture of this suspect will be circulated as soon as one is retrieved.