Young people are being groomed into gang culture by a criminal element, a chief constable said today.
Norfolk police chief Ian McPherson said teenagers are being inadvertently drawn in by internet social networking sites.
Mr McPherson, the Association of Chief Police Officers spokesman on children and young people, said parents will be shocked by the extent of the problem.
"This is not about faith or race - this is about groups of diverse young people who are stepping outside society's rules," he said.
"We were worried that some of the young people were being groomed by the more criminal element and pressured by their peers.
"Those not familiar with gang culture would be shocked by the evidence we have gathered over recent months.
"As police officers - and parents ourselves - we are appalled by the picture that's been drawn."
Mr McPherson, who launched a plan to tackle the problem in Norwich today, said gangs had gathered many hundreds of associates using websites such as Bebo.
They use the internet to talk in a "distinct street language, boast about their relationships and sexuality, post videos of mindless acts and display provocative images, including weapons and cannabis plants", he said.
"Social networking sites are an important method of communication and recruitment for gang members," said Mr McPherson.
"What may appear innocuous on screen may well be part of their coded language.
"What is really worrying is that many young people are being inadvertently drawn into associating with gang members without knowing they are doing so."
Mr McPherson said officers built up a dossier over recent months on three well-known gangs operating in Norwich.
It revealed they had intimidated others, carried out crime and been prepared to use weapons to "increase their fear factor".
"It's a scourge of society and we will not shy away from using the full force of the law to disrupt activities which cause misery to many," he said.
"The key to preventing young people becoming drawn in is to engage with them. This is critical as we do not want to unnecessarily criminalise them.
"Some of the young people were really quite dangerous and we were worried innocent youngsters would be injured or even killed. We have tried to learn the lessons from some of the other areas which have already seen the problems associated with gangs to prevent escalation here in Norfolk."
Norfolk police have used anti-social behaviour orders, dispersal orders and stop-and-search powers to tackle the problem.
High profile patrols in areas where gangs meet have also been carried out.
Mr McPherson said officers would continue to crack down on the problem.
"We won't tolerate any kind of gang criminality or anti-social behaviour," he said.
"The message to gang members is simply this - we know who you are, we know what you do and we know where you operate."
He added: "We will do whatever is necessary to maintain the rights of everyone to live without fear or intimidation. We will disrupt activities of gangs and individuals who are intent on spoiling the quality of life we enjoy here."Reuse content