Police secure the murder scene in Larkhall Park, Lambeth
Five people have been arrested after a 16-year-old boy was killed and another teenager was injured during a stabbing in a park in south London.
The 16-year-old was dead when emergency crews arrived at Larkhall Park, in Lambeth, on Monday night.
The second boy, 17, is said to be in a stable condition in hospital. He has been arrested on suspicion of assault.
Two boys, aged 15 and 17, and two men, aged 21 and 25, are being held on suspicion of murder.
All four were treated in hospital for stab wounds.
Residents said two gangs clashed on the nearby Lansdowne Green Estate at the time of the stabbings.
They told officers they had heard shouting and screaming in the park.
One man, who did not want to be named, said: "There was a big fight - I heard it was some sort of retaliation after something else that happened earlier on."
Most of Larkhall Park was sealed off following the incident
Another man, who works as a youth football coach in the park, said the incident began when teenagers who live on the rival Hemans Estate strayed into the area.
He said: "It is the same old story. They think they are gangsters. They have empty minds. They watch these videos and think it is real."
Several witnesses said a Staffordshire bull terrier-type dog was also stabbed.
Most of Larkhall Park was sealed off following the incident.
A stretch of Wandsworth Road, which runs along the western side of the park, has also been closed to traffic.
The teenager's death brings the total number of young people to die in violent circumstances in London this year, to seven.