Tomorrow Theresa May, the Prime Minister, will host a major knife crime summit at Downing Street as the police desperately try to get a grip on the rising tide of violence.
The north London stabbings, which police are linking, began yesterday when a 45-year-old woman was approached by a man and knifed once in the back as she walked along residential Aberdeen Rd in Edmonton.
Locals who heard the woman's screams ran to her aid and tended to her until the paramedics arrived.
She was taken to an east London hospital where her condition was described as critical.
Around four hours later the same attacker is believed to have approached a 52-year-old man on Park Avenue in Edmonton around 5km away stabbing him more than once.
The victim was taken to an east London hospital for treatment where his condition was described as not life threatening.
A few hours later, police received reports that another person had been stabbed in the area.
This time they found a 23-year-old man close to Seven Sisters Tube station suffering from knife injuries.
Police said initial investigations indicated he had been stabbed in the Silver Street area around 5km away but made his way to Seven Sisters before collapsing.
The last incident took place when police received reports that a man had been stabbed in the back in Brettenham Road in Walthamstow.
Police said while the victim's injuries were not life threatening, they were potentially life- changing.
Detective Chief Inspector Stuart Smillie from the Met Police said they were treating the incidents as a potential mental health issue and urged people to remain vigilant.
He said: "Police are treating the four stabbing related incidents as potentially linked. The four victims are all 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 he has approached from behind without warning.
There have been more than 20 fatal stabbings across the capital since the start of the year, with two knife murders in the past few days.
On Friday 25-year-old Zahir Visitor was stabbed to death in St John's Wood, while a man in his 40s was murdered on Saturday in Clapham when he was ambushed by a group of knife wielding men as he sat in his car.
Elsewhere a 24-year-old man was stabbed to death in Birmingham on Saturday and a 29-year-old man died after being stabbed in the neck in Liverpool on Friday.
