Emergency services were called to reports of a stabbing on Lavender Hill at 3.26pm today (October 21).
A 19-year-old was treated at the scene for stab wounds.
He was taken to hospital with injuries believed to be life-threatening.
Police await an update on his condition.
No arrests have been made, and police are urgently making enquiries.
Anybody who witnessed the incident – or who has information – is asked to call 101, quoting the crime reference 4781/21OCT.
A spokesperson for the Metropolitan Police said: “At 15:26hrs on Tuesday, 21 October, officers attended Lavender Hill, Wandsworth, alongside the London Ambulance Service following reports of a stabbing.
“A 19-year-old was treated at the scene for stab wounds.
“He was taken to hospital with injuries believed to be life-threatening.
“We await an update on his condition.
“No arrests have been made, and police are urgently making enquiries.
“Anybody who witnessed the incident – or who has information – is urged to call 101, quoting crime reference 4781/21OCT.”
