Four men have been arrested on suspicion of murdering a 16-year-old boy in south London.
John Ogunjobi was found unconscious on a street in Tulse Hill on 5 November and was pronounced dead shortly before midnight.
The teenager died in front of his devastated parents, with one witness describing his mother’s screams.
A post-mortem examination revealed the cause of death was a stab wound.
Scotland Yard said detectives investigating the fatal stabbing made four arrests on Monday.
Four men – aged 22, 20, 21 and 23 – were arrested on suspicion of murder and taken into custody at south London police stations.
Officers are returning to the scene a week after the boy’s murder to appeal for witnesses.
Detective Chief Inspector Richard Vandenbergh, who is leading the investigation, said: “I am appealing to anyone who has information that could assist this investigation to come forward and speak to police.
“We believe the victim was attacked by a number of suspects and the altercation would have undoubtedly drawn the attention of those who were in the vicinity.”
One of John’s friends, who had dinner with him on the evening he died, said: “He was bubbly. He was the friendly type. He was respectful. He had manners.”
Friends also said he was an aspiring rapper who went to school at Park Campus in West Norwood.
The 16-year-old’s killing followed four other fatal knife attacks in London in less than a week.