A teenager has been left needing surgery after being repeatedly stabbed in an attack which was allegedly recorded on a mobile phone.
Harrowing footage of the assault in Brixton, south London, has been released by Scotland Yard as detectives attempt to trace the suspects.
The 18-year-old victim was stabbed, whipped, punched and kicked by at least three assailants at the Dallas Chicken takeaway on Brixton Road on Monday at 5.30pm.
During the attack, one of the attackers can be seen drawing a knife and thrusting it forward while holding a mobile phone in his other hand.
Scotland Yard said the victim, who has not been identified, was hit in the face with a belt then stabbed several times.
As he collapsed to the floor, the victim was stabbed once more before being kicked in the head.
The teenager suffered four stab wounds to his leg, one to the abdomen and one to the arm.
He was taken to hospital and underwent surgery on his abdomen.
The victim has since been discharged but requires further surgery on his arm.
According to witnesses, there were a further three suspects on bicycles waiting outside the takeaway shop at the time of the attack.
They all left together after the assault and made their way northbound along Brixton Road.
Anyone with information is asked to contact police via 101, on Twitter @Metcc or Crimestoppers anonymously on 0800 555 111.