Shocking and graphic video from a McDonald's in Brooklyn, New York, shows the moment a gang of teenage school kids viciously attacked a 15-year-old girl for nearly three minutes, as a large crowd of adults and children failed to intervene.

Police later said that they were made aware of the incident after workers from the fast food chain dialled 911 - but no one else watching attempted to contact authorities.

The video was uploaded by Janae Aiko, who criticised people for not breaking up the fight. It shows between four and six teenage girls attacking the 15-year-old, continually throwing a barrage of punches to the girl's back and face as she is swung around the room. The McDonald's is packed with people watching the after-school fight, with many cheering and filming the scene on their phones.