Senior police officers are increasingly concerned about the young age of children walking the streets with guns tucked in their trouser waistbands. Scotland Yard has directed its latest anti-gun advertising campaign at the 11-16 age group.

The pattern of youthful gunmen is being repeated across Britain with police forces reporting the growing involvement of children in shootings. The weapons are displayed as a show of street credibility and bravado, or are obtained by children on the periphery of drug gangs because they feel that they need protection.

Youth workers involved in the fight against gun crime say that girls, whose role used to be confined to smuggling weapons into nightclubs for their boyfriends, are also beginning to arm themselves with pistols as “fashion accessories”.

Replica weapons crudely converted to fire live rounds are used widely, but there is evidence from crime scenes of the increased use of semi-automatic machine pistols such as the Mac-10. The weapons are being smuggled in from the United States, Eastern Europe and the Middle East and are used most widely by organised gangs involved in the drug trade. But, more and more, firearms are being used by teenagers to settle trivial arguments.

Detectives investigating the shooting of two teenagers in a McDonald’s restaurant in Brixton a week ago believe that it followed a verbal spat between youths who were known to each other. “There was an altercation that afternoon. It was not gang related or a criminal feud,” a police source told The Times. “What might have been a noisy argument or a fist fight ended up with someone pulling out a weapon and opening fire.”

The two 17-year-olds injured in the shooting are making good recoveries. Scotland Yard said yesterday that two males in their mid to late teens had been arrested in connection with the incident.

“We now know prior to the shooting that the victims were involved in a brief verbal argument with some other people in the restaurant and then three to four minutes later the shooting occurred,” a police spokesman said.

“It is also now known that the suspect was in the restaurant prior to the shooting and may have escaped on a pushbike afterwards.”

What police statistics describe as “gun-enabled crime” is falling across London. In the year to August, it went down by 21 per cent. Incidents involving gun crime in the black community fell by 16 per cent in four months.

But there are exceptions to the pattern. Guns are commonplace in South London, most notably in the Borough of Southwark, where the number of firearm incidents rose from 242 in 2004-05 to 300 in 2005-06. Southwark contains the hotspot area of Peckham, where rivalry between two gangs of youths, each with access to guns, is behind the violence.

The Peckham Boys, members of which were involved in the murder of Damilola Taylor in 2000, and the Ghetto Boys are being watched by Scotland Yard’s Operation Trident task force. Last month two schools in Peckham closed early after police received “specific intelligence” that a drive-by shooting was to be carried out by one gang in retaliation for an attack on one if its members. The school closures followed a shooting at a community centre in Deptford and shots fired in a revenge hit on youths playing basketball in Peckham. In one house raid police seized a Mac-10 and a Walther PPK hand gun and pressed charges against a young man and a girl aged 17.

Justin, who is 21 and from South London, used to carry a gun. He said that association with older members of drug gangs was the way in which most youths came to be armed.

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