WARNING DISTRESSING VIDEO: The sickening violence was captured outside a school as staff promised to help police probe the "clearly upsetting" footage said to involve adults and children
Horrifying footage shows the moment a teenage girl is beaten and dragged along a pavement by her hair outside a school.
Mobile phone video shows a girl wearing a pink tracksuit grab the defenceless schoolgirl by her hair and viciously punch her head.
As the beaten girl lies helpless another girl continues the sickening attack as onlookers film the violence.
The video emerged on the Facebook page of comedian Robin Armstrong, who said he was sent footage of a woman and a gang of girls attacking other girls in Middlesbrough.
Two separate brawls can be seen in his Facebook post, including the one with the pink tracksuit attacker.
The school said the "clearly upsetting" footage showed adults and children fighting.
Teachers have vowed to help police as they launch an investigation.
Executive Principal Mark Hassack said: "The video we have seen is clearly upsetting as it involves children fighting and adults getting involved, something we would never want to see.
“We take the safeguarding of all children extremely seriously, inside and outside the academy in line with our robust behaviour and safeguarding policies.
“Any reports of criminal behaviour, anti-social behaviour or bullying incidents to the academy will follow agreed Police and academy procedures. “We are co-operating fully with the police in relation to this incident.”
Mr Armstrong, who posts videos of himself slamming trolls and bullies, said the footage was among the worst he has ever witnessed.
He said: "It even caught me off guard. I post these clips as I like to think it gives the victim a little bit of revenge,” he said.
“But this was just disgusting and even the kids watching were saying it wasn’t fair.”
His Facebook followers branded the attackers "heartless" and questioned why no-one intervened to halt the beating.
The comic added: "Why isn’t someone wanting to be a hero and step in?
“Maybe they are scared, but you also have to think maybe why they are recording is so they can take it back and show their parents or someone else and let people know what happened.
“It’s a funny old world now with camera phones, as nobody can get away with anything.”
A Cleveland Police spokesperson said the incident occurred at around 7pm and that enquiries are ongoing.