A teenager has died and a man was injured after they were gunned down in a street.
The pair were shot in Hindrey Road, Clapton, east London, at 8.20pm on Saturday, Scotland Yard said.
Paramedics rushed them to hospital where the younger victim, 19, later died. A 32-year-old man was understood to be in a stable condition, police said.
Detectives from Operation Trident, which investigates gang-related crime, are hunting two suspects seen running from the scene.
One is black, police said, while the second is light-skinned, possibly of Asian or Turkish appearance.
They were seen running away from Hindrey Road after the shooting towards the nearby Pembury Estate.
Police said there was as yet no clear motive for the shootings, and no-one has been arrested.
"At this very early stage we must retain an open mind regarding the circumstances of the incident and any motive," the spokesman said.
"Detectives from Trident are leading the inquiry and an incident room will open in the morning."
A post-mortem examination is to be arranged. Witnesses to the shooting or anyone with information about the incident are asked to call police on 101 or Crimestoppers on 0800 555 111.