A 20-year-old woman and a 19-year-old man were shot in South Croydon in the early hours of yesterday morning.
The pair were injured in the attack at a flat in Kingsdown Avenue at about 3am.
The Metropolitan Police said they were being treated in hospital for gunshot wounds, not thought to be life-threatening.
The woman is understood to have been shot in the back and the man shot in the thigh.
No arrests have been made.
The incident happened near Purley Oaks Station
London Ambulance Service said it was called to reports of a shooting at 3.19am.
It sent three ambulances, a duty officer and a motorbike to the scene and took both victims to a south London hospital as a priority.
Both were conscious and breathing.
Police have appealed for anyone with information on the shooting to come forward.
Detective Chief Inspector Jason Prins said: "We are in the early stages of our investigation and I would like to hear from anyone who may have witnessed the incident or the aftermath.
"Two people have been left with injuries and I keen to hear from anyone who may have any information about the person or persons responsible."
Anyone with information about this incident can 0208 247 4877 or Crimestoppers anonymously on 0800 555 111.
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