Police say that an incident on the Old Kent Road on Wednesday afternoon in which a 20-year-old man was stabbed is linked to the death of a 21-year-old man on the Aylesbury Estate in Walworth.
Police, the London Ambulance Service and the air ambulance were called at approximately 5pm on Wednesday to reports of an assault on the Aylesbury Estate.
Two men were found suffering from stab wounds and were taken to hospital.
A 21-year-old man died soon after arriving at hospital. An 18-year-old man has since been discharged from hospital.
Ten minutes before the call to the Aylesbury Estate, police were sent to the Old Kent Road, SE1, where a 20-year-old man had been stabbed. He was taken to hospital and has now been charged.
The Metropolitan Police has set up an incident room in Sutton under Detective Chief Inspector Amanda Hargreaves.
Anyone with information is urged to contact the incident room on 020 8721 4155 or anonymously on Crimestoppers on 0800 555 111.
Three males aged 27, 21 and 20 have been arrested in connection with this incident and remain in custody at separate south London police stations.