Police continue to investigate a spate of unconnected stabbings in south London after a 22-year-old was killed and 11 others were wounded since Friday evening.
The Metropolitan Police said they have enacted additional stop and search powers and more officers have been deployed in response to the multiple incidents.
On Friday, five incidents were reported in south London between 6.56pm and 9.12pm.
A 22-year-old man injured at a property in Wisbeach Road, Croydon, was pronounced dead at the scene.
Scotland Yard said a group of males attended the address and the victim was stabbed in an altercation.
One resident, who has lived at the block of flats near the scene of the fatal stabbing for more than 20 years, said she saw police and medical staff trying to save a heavily bleeding young man.
She said the man’s mother later showed up “crying and in pieces”.
The witness, who declined to be named, told reporters the man was bleeding from a deep cut to his leg and there was “blood everywhere”.
She said: “I heard someone shouting but it’s normal because people drink outside, I came down and saw two police and two ambulance guys on the ground with him.”
She said she saw medical staff make an incision in his torso, adding: “They tried really hard to save him but there was a lot of blood.”
Police previously said another man was taken to hospital before officers arrived with non-life-threatening injuries.
Regarding the murder probe, Detective Chief Inspector Martin Thorpe, from the Met’s Specialist Crime team, asked residents who saw or heard anything after 8pm to contact police.
He continued: “I am aware that this was one of a number of violent incidents in and around the south London area on Friday evening but there is nothing to connect these incidents together at this time.”
No arrests have been made in the murder investigation.
Nine other men were wounded on Friday. Two sustained serious injuries but neither is now in a life-threatening condition.
Two people were arrested after a man in his 40s was found with a stab wound at an address on Dingwall Road, Croydon.
The victim was later arrested on suspicion of affray and a 38-year-old man has been arrested on suspicion of GBH.
Gold Commander for London this weekend, Ade Adelekan, said investigations were ongoing regarding the circumstances of Friday’s incidents but said they were “being treated as isolated”.
At around 11.20am on Saturday, officers were called to reports of a fight in Hadleigh Grove, Couldson, south London.
A man in his 20s had been stabbed and was taken to hospital with non-life-threatening injuries. Two men have been arrested.
Shortly after 3pm, police were called to a stabbing near the junction of London Road and Oakfield Road in Croydon.
A 24-year-old man was taken to hospital with non-life-threatening injuries.
A section 60 order granting police additional stop and search powers will be in place until 7.30am on Sunday.
Superintendent Andy Brittain, Deputy Commander for the South Area Command Unit, said: “I understand that the events of the past 24 hours will have caused concern for many people in our local community.
“The violence we have witnessed is senseless and our thoughts are with the family of the 22-year-old man who tragically lost his life.
“I want to reassure the community that our borough is safe. Investigations are well underway and four arrests have been made.
“I also want to clarify that most of the people involved in these incidents have been adults.”
Police are also investigating the fatal stabbing of a man in his 20s in Willesden Lane, north-west London.
A second male, who is believed to be a teenager, is in critical condition hospital, the Metropolitan Police said.