A teenage boy is being treated for multiple stab wounds in an east London hospital after he was attacked in Druid Street on Thursday night.
Police were called to Druid Street at about 8.30pm on Thursday to reports of a stabbing.
When they arrived, officers found a 17-year-old boy suffering from multiple stab wounds.
The Downside Fisher Youth Club posted a message on Twitter saying that they were "shocked and saddened by the serious violent attack on one of our local young members who managed to escape into the youth club for safety".
The London Ambulance Service and air ambulance were called to the scene and the victim was taken to an East London hospital where his condition is described as critical but stable.
A Metropolitan Police spokesman said that officers are investigating the possibility that the incident is linked to an earlier disturbance in Tanner Street.
Five males have been arrested in connection with the incident and remain in custody at South London police stations.