The findings, shown exclusively to The Times, came after interviews with 11,400 London children about the scale of the gun problem on city streets.

The results were disturbing: not only did one in ten teenage schoolboys say that he had carried a gun or a replica gun in the past year, but 6 per cent of the 11 to 15-year-olds said that they had fired a real gun. One in seven said that they knew someone who had “brought a gun or a real-looking gun” to school. The unpublished report commissioned by the Government and the Metropolitan Police concluded that there was “some concern” over the reasons offered for carrying guns, real or imitation.

The researchers from the charity Communities that Care said that a third of those who said that they had carried a “gun” in the previous year had done so for self-defence. “This suggests there is a real level of fear among this age group,” the authors said.

The study also questioned whether the children were imitating adults in their communities who bore real guns, giving warning that a new generation of armed criminals could be in the making because the children could be “at risk of drifting into gun-related lifestyles”.

The survey, of children in six inner-city London boroughs, was carried out by anonymous questionnaire. Both boys and girls were remarkably familiar with weapons at a young age, with one in ten carrying knives, and one in thirteen who had carried another weapon such as self-defence spray.

About half of those who reported carrying a gun said that it was a BB gun, which fires ball bearings, with the next most common category being an airgun. Only 1 per cent said that they had carried a real handgun although 6 per cent said that they had fired one. Eight per cent of children said that they could easily get access to a handgun and 20 per cent a replica gun, many of which can be converted into deadly weapons. Police officers have already given warning that the number of youths carrying firearms has doubled in the past five years and senior detectives say that many teenagers see them as fashion accessories.

Last August a 12-year-old boy with a shotgun attempted to rob a shop in Wolverhampton while in April a boy of 10 was arrested after shooting a pregnant teacher in the face with a ball-bearing gun. In May a 12-year-old boy was shot through the eye and killed while playing with an air rifle in his bedroom with a friend.

Last month the Government published the Violent Crime Reduction Bill, which proposes raising the age at which people can buy replica weapons and increases the penalties for carrying them in public places. Ministers say that there is a rise in the use of imitation firearms as they only carry a six-month sentence compared with a mandatory five-year sentence for a real one. Senior police officers said last night that they encountered youngsters with guns — a majority of them replicas — every day.

Chief Inspector Steve McGarry, a member of the criminal use of firearms group of the Association of Chief Police Officers, said that there had been a 66 per cent rise in the number of reported incidents involving replica firearms.

He said: “When members of the public phone us they do not say that there’s some children at the end of the street playing with a BB gun. They see a kid with a gun and the police have to respond with its armed response unit. What could then happen is that a 13-year-old kid is challenged by an armed officer. Throw drugs or alcohol into the equation and you don’t know how that child will react.”

Chris Keates, the general secretary of the NASUWT teachers’ union, said last night: “These statistics are not necessarily surprising but they are worrying. A gun, replica or otherwise, poses a danger in the classroom. If a pupil pulls a gun, a teacher has to react as if it’s real regardless of whether it turns out to be a replica.”

Explore Education

• Schools

• GCSE & A Level Results

• Good University Guide

• Sunday Times University Guide

• Student

• Young Times

Times recommends

• Can Dr Evil get boys to start reading again?
• Deputy head who stole thousands from school struck off
• Failure to master maths adds up