A video of two Cardiff schoolgirls having a vicious fight has been removed from the internet after criticism from anti-bullying campaigners.
The video shows the girls surrounded by a crowd of children
One of the girls in the Cardiff film, from Llanishen High School, ends up with blood on her face.
Anti-bullying charity Kidscape had called for the video to be taken off.
The charity said parents of the girls fighting and watching should be shown the film to drive home the reality of what is happening.
California-based YouTube allows users to post content directly. The video, recorded on a mobile phone, had apparently been posted by a 15-year-old girl.
Among videos still online is one claiming to be a fight at another school in south east Wales, involving two boys.
Neither pupil has been excluded from Llanishen High School
Iwan Guy, a national executive member of the National Association of Head Teachers said he had found the footage "very disturbing".
"Both boys and girls have been scrapping as long as there've been boys and girls. But it's the mentality now and the way they think it's OK to stage a fight - because this is a staged fight, it's not one that just happened," he said.
"What is disturbing for me is the misuse of the technology - of both the phones and the internet.
"I have to ask parents do you know what your children are doing with their mobile phones? Do they know what they're doing on the internet?"
John Carr, new technology adviser to children's charity NCH, said the fact it was so easy for children to reach a "large audience", encouraged more staged fights than would otherwise happen.
Mr Carr said: "There was a case in London not long ago where a young lad was killed and the whole thing was videoed over a mobile phone.
"The judge was quite clear that it was partly because they wanted to film what they were doing that caused the attack in the first place."
Harsh blows are given, with one girl ending bleeding from the face
A teenager at Coed Mawr community centre in Bangor said youngsters often wanted fights recorded to impress their friends.
She told BBC Wales: "Everyone records it so you think you're cool, but then it happens more. If it's been on the internet once they know that they're gullible, so they just do it again and again. It's the same people usually.
"If you put it on a site you can tell all your mates, so it soon gets round."
The Cardiff fight begins with the taller of the two talking to the other girl, as they are surrounded by other children.
The grainy footage, which is less than a minute long, shows them wrestling with each other for some moments before the smaller girl kicks upwards twice and repeatedly hits the taller girl in the face.
The bigger girl is pushed to the floor and a number of other youngsters join in and start kicking and hitting her. She ends with blood on her face and is led away by other girls.
A spokeswoman for Cardiff council's education department said two pupils from Llanishen High were involved in a "distressing altercation" out of hours and not on school property a few months ago.
Police dealt with the incident and it was referred to the school.