Fight between Northern Ireland teens as baying mob looked on is probed by police
These are the shocking images showing a brawl between two teenage boys in front of a jeering mob of around 100 people.
Young people ran on to the street in the Cregganburn and Glen areas of Londonderry and followed the fight as the two youths kicked and punched each other.
It ended when one of them managed to evade the pack and run to safety.
Local residents were said to be stunned by the fracas.
Police have pledged to tackle the issue robustly.
Independent councillor Sean Carr said: "These young people just seem to appear out of nowhere, but they clearly knew there was going to be a fight taking place.
"This is shocking and people living around here have been stunned at the violence and the mob mentality of those watching.
"I don't think these young people have any idea of the serious consequences that could have come as a result of this fight.
"All too often we hear of someone hitting the back of their head on the ground during a fight and that's enough to take their life.
"This is not entertainment, this is sick and it is shocking that hardly anyone tried to intervene and stop these boys fighting."
Mr Carr urged parents to make sure they know what their children are doing on social media, and where they are going when they leave home.
Foyle SDLP MLA Mark H Durkan echoed this call, saying parents have to be more aware.
"The scenes in the Glen were pretty frightening for residents, passers-by and, I'd say, the vast majority of young people caught up in it themselves who probably just came along because their friends were on about it," he said.
"Parents need to have a word with their children and warn them how easily fighting or just being around a fight could result in really serious harm to them or to someone else.
"It can also lead to their expulsion from school and a criminal record.
"None of us want that."
The PSNI said: "Shorty before 6.15pm it was reported that around 100 young people had gathered in the area and were throwing stones at each other. The youths dispersed in the Northern Road area when police arrived.
"It is critical that when young people choose to engage in anti-social behaviour, they understand that it is unacceptable and it must stop. We do not want to criminalise young people, however if offences are identified we will deal with them robustly."