Southwark Police are appealing for any witnesses or information concerning a serious stabbing in the Old Kent Road on Thursday 23 August.
The incident happened at around 10.30pm on Thursday night near the junction of Old Kent Road and Trafalgar Avenue.
A 17-year-old man was attacked following a chase by a large group of between eight to ten men. He was punched, kicked and stabbed during the course of the attack.
The victim was taken to hospital where condition is said to be serious but stable.
The incident is being investigated by Southwark CID.
"The Old Kent Road is a major arterial route through south London and the area where the incident took place was very busy at this time of night," says DI Kiaran Wood.
"I am appealing for anyone who saw anything of the incident, whether a pedestrian or driving through or travelling on a bus. Did you see or hear anything suspicious?"
The suspects are described as a group of between eight and ten young black men, from late teens to early 20s. It is possible that they were using vehicles.
The number to ring with any information is 020 7232 6166, or Crimestoppers on 0800 555 111 if you wish to remain anonymous.