Three people have been arrested after a youth was shot dead and two teenagers were stabbed.
The Metropolitan Police said officers were called to reports of an assault near Gannet House on the Pelican Estate in Peckham, south-east London, at about 4.30pm on Wednesday.
"At the same time officers were informed of a male youth claiming to be stabbed in nearby Peckham Road," a force spokesman said.
"While looking for these victims, officers discovered a male youth in a stairwell at Heron House, Pelican Estate, suffering a gunshot wound.
"London Ambulance Service were called but he was pronounced dead at the scene."
At the same time officers discovered a 17-year-old male at an address in Gannet House suffering a stab wound. He was taken to a south London hospital where is condition was described as "stable".
Police were alerted to a third victim, an 18-year-old male, after he arrived at a separate south London hospital, also suffering from a stab wound. He is also described as being in a stable condition.
"Officers are treating all three incidents as linked at this early stage," the Met spokesman said.
"Three males have been arrested in connection with the investigation.
The age of the gunshot victim has not yet been confirmed.