Police are investigating after a man suffered injuries which could have been caused by a gun in an incident in Lambeth Road on Thursday night.
Police were alerted at about 10.30pm after a man with neck injuries presented himself at St Thomas' Hospital.
Officers believe that the man's injuries could have been caused by a firearm.
Investigations led officers to examine an incident which took place at the junction of Lambeth Road and St George's Road, near St George's Cathedral.
The section of Lambeth Road between St George's Road and St George's Circus was closed for several hours and bus services were diverted.
The victim, a male in his late teens, was treated for his injuries and discharged from hospital.
A Metropolitan Police spokesman said that inquiries were continuing.
For the latest local news and events direct to your inbox every Monday, you need our weekly email newsletter SE1 Direct.