Very little is known about teenage gangs in Britain. There has been no national research and the government remains unconvinced that they pose a serious problem.



Perceived thinking has it that youth gangs are little more than an irritant, indulging in mainly minor crimes such as graffiti, vandalism and anti-social behaviour.



But, in the largest survey of youth gangs ever undertaken in this country, Dispatches discovers that the vast majority of youths gangs, even in areas not known for gang activity, are committing, and suffering, horrific levels of violence.



Two thirds of the gangs had been involved in a stabbing and a quarter in a shooting. Around two thirds committed street robberies. Most of the victims are other youths.



Fights can start over something as minor as looking at someone 'disrespectfully' - and weapons are frequently used. Three quarters of the gangs surveyed carried knives, and a quarter had members who carried real or replica guns.



But perhaps the most alarming revelation is that all the gangs operate under the same code of silence as their adult criminal counterparts. The law of the streets dictates that no one talks to the police.



The result is tit-for-tat violence that often escalates out of control. And even when people are seriously injured, there are seldom prosecutions, because of the culture of silence.



Neither is the problem confined to areas of previously known gang-activity. An exclusive survey for Dispatches reveals that youth gangs exist in the suburbs as well as the inner cities.



The majority of gangs in the survey had 20-60 members. Two gangs had over 100 members. The average age of gang members was 15-16. But some had members as young as nine.



Dispatches: Gang Wars broadcasts on Channel 4 at 9pm, Sunday June 8