A girl believed to be 15-years-old has been shot dead at a home in east London, Scotland Yard said.
Police were called to reports of a shooting at a residential address in Eastway, Hackney shortly before 4pm on Saturday.
The London Ambulance Service and London's Air Ambulance attended but the teenager was pronounced dead at the scene.
Three boys all aged under 18 were arrested nearby and taken to an east London police station where they remain in custody.
A Metropolitan Police spokesman said: “Officers believe they know the identity of the deceased and have begun informing family, however they await formal identification.
“A post-mortem examination will be held in due course.
“Detectives from the Met's Homicide and Major Crime Command are investigating.”
Police are standing guard outside the terraced house where the shooting happened.
The street, which backs on to Wick Woodland, remains closed to allow detectives to carry out their inquiries.
Police flooded London's Hackney borough after the incident, with officers from across the capital drafted in to reinforce local officers.
Anyone with information is asked to call Crimestoppers on 0800 555 111.