A teenage girl has been arrested on suspicion of murder over the stabbing of a 22-year-old man.
Ayodeji Habeeb Azeez was stabbed in Anerley, south London on Sunday.
Mr Azeez was chased down the street before he was stabbed. He was murdered in broad daylight in Samos Road.
Emergency services were called at 12.30pm on Sunday November 4 but he died half an hour later, despite efforts from paramedics.
Mr Azeez who was from Dagenham in east London, was the 121st person to be murdered in the capital this year and the fourth of five people to have been stabbed since Halloween.
Detective Chief Inspector Mark Cranwell, from the Met's Homicide and Major Crime Command, said: 'This attack took place in the middle of the day, in broad daylight in a residential street.
'It goes without saying that this incident would have stood out in what would normally have been a quiet environment.
'It appears that four or five male suspects were involved in the attack; both they and Ayodeji were seen to run into Samos Road from Grace Mews. By this point Ayodeji had been attacked. The suspects fled in one direction while Ayodeji went the other way before he collapsed.
'I am appealing to anyone who was in the area on Sunday afternoon and saw this attack, or the events surrounding the attack, to come forward and speak to police. This includes trying to establish if anyone was with Ayodeji when he was attacked.
'My officers are making progress as to why Ayodeji was in the area, why he came to be attacked and who was responsible for his murder, but we need information from the public to assist us in keeping the momentum of this investigation moving forward.'
Police had previously arrested two men, aged 19 and 21, on suspicion of murder on Sunday, who were later released under investigation.
Earlier this week, Britain's stabbing epidemic reached its peak, as the country saw saw six stabbing attacks take place across the country in just over 24 hours.
Four of the six stabbings had taken place in London, one in Great Yarmouth and the other in Birmingham.
Police arrested three men on suspicion of murder in Birmingham after a man was found dead in the street on Tuesday night.
Footage from the scene in Sparkbrook showed officers laying a white sheet over the victim's body. It is believed the incident was a stabbing.
Also on Tuesday, officers were called to an alleyway in well-heeled West Hampstead in North West London at about 8pm after reports of yet another knife attack.
The boy was found on a road named after rock legend Billy Fury, close to a street of multi-million pound houses and the three train stations in the area.
On Wednesday in Hackney, paramedics raced to the scene near the Olympic Village after police were called to the 'disturbance' shortly before 2pm.
A group of people ran out the front of the square after the attack, and officers said no one could pass the cordon because a police dog was on the way.
One resident said he heard that a suspect leapt into gardens and was hammering on windows to try to get away from the scene by going through people's houses.
The man was taken to hospital and a forensic scene was put in place at the site near Hackney Wick train station, but no arrests have been made.
Elsewhere in London on Wednesday a teenager was left with 'life-threatening injuries' after a stabbing in Shepherd's Bush, while on the other side on the city in Enfield a man in his 20s was 'repeatedly stabbed'.
Police are working to stem the bloodshed after five men and boys were stabbed to death in one week.
It began with the murder of father Rocky Djelal, 38, who was killed in Southwark Park, Rotherhithe, in a targeted attack last Wednesday.
The next evening 15-year-old Jay Hughes, also known as Jai Sewell, was killed by a stab wound to the heart in a premeditated attack in Bellingham, South East London.
On Friday, college student Malcolm Mide-Madariola, 17, was knifed to death outside Clapham South Tube station.
The latest victim, a 16-year-old boy who died after being stabbed in Tulse Hill, south London on Monday has been named by Scotland Yard as John Ogunjobi. Friends said he was a drill rapper known as JaySav.