A teenage boy was battered with a belt and a bike lock during a horrific street attack caught on camera.
Police said the boy, believed to be aged 17, and two teenage girls were attacked after a dispute in a takeaway shop turned violent.
A person travelling on the top deck of a bus caught shocking video footage of a young man attacking the victim with his belt, repeatedly whipping him around the head.
The incident happened outside Chicken Cottage in Harrow, north London.
Commenting on Facebook, Sophia Imran said the boy being attack was her younger brother.