London, UK - Detectives have released CCTV outside a McDonald's burger shop showing a brutal attack by a gang of youths on a teenager.Police in Barking and Dagenham Borough investigating an assault outside a restaurant have issued CCTV footage of four teenagers they wish to identify and speak to in connection with the incident.On Thursday, 5 May, police were called at around 11pm to a report of an assault outside McDonalds, East Street, Barking.The assault on a teenager occurred earlier that evening at 8:30pm. A gang of teenagers had approached the 15-year-old victim and asked him what he was doing and where he was going.