A particularly worrying trend to emerge from the survey of over 11,000 secondary school pupils is the apparently strong link between drugs and the possession of offensive weapons. Just over a third of Year 10 boys who had never taken any illegal drugs claimed to have friends who carried guns or knives, compared with 46 per cent of those who had taken one drug, 51 per cent of those who had taken two drugs and 70 per cent of those who admitted using three or more drugs. Comparable figures for girls showed a similar rise from 10 per cent for those who had never taken drugs to 36 per cent of those who had used three or more substances.

Since the survey shows a similar link between higher amounts of income and friends who carry offensive weapons, researchers suspect that dealing in drugs may be connected to higher levels of weapon-carrying among school pupils. Similar correlations occur with drinking, smoking and gambling.

John Balding, head of the Exeter University’s Schools Health Education Unit which carried out the research for Channel 4‘s Dispatches programme, said: “This link appears to be a matter for concern.”

He believes the research is particularly worrying because it is likely to under-report the true levels of weapon-carrying by pupils. It covered 64 secondary schools, mostly local authority mixed comprehensives, in seven regions: Cornwall, Cumbria, Devon, Essex, North-West Lancashire, West Midlands and Teeside, and was part of the wide-ranging schools questionnaire the unit has been using for the past 20 years.

The report, called Cash and Carry, points out that none of the districts sampled correspond to any known trouble spots where weapon-carrying and physical violence are an issue. Yet it found that offensive and defensive weapons are carried by 22 per cent of all 11 to 16-year-old pupils.

Coming in a week when the Government’s working party on school security published its report to widespread approval, when yet another pupil was excluded in a highly-publicised wrangle over school violence, and when Labour called for a raising of the minimum age at which a gun licence could be held in the wake of the Dunblane school massacre, the research has further fuelled the debate. The National Union of Teachers also published its own survey of violent incidents, covering more than 2,000 schools.

Footage shot undercover by a teacher in an unnamed secondary school, showing pupils with various weapons, has gone some way to support the argument propounded by the National Association of Schoolmasters Union of Women Teachers that pupil discipline should be tightened and staff not expected to act as police.

One school leaver in the Dispatches film described the weapon culture in his school: “If you say ‘look, I’ve got this knife, it’s the biggest knife in the school, then you’ve got power’,” he said. Another told of the open trade in weapons in his school, and said they were needed for protection. “If anyone tried anything you just whack ‘em up. You can’t just stand there and let other people take liberties with you,” he said.

Professor Michael Barber, Dean of the Institute of Education, described the Exeter research as ground-breaking.

He added: “You are also getting at a deeper issue - whether there’s something going on in the attitudes of young people that neither teachers, parents nor any of the other social agencies have been able to understand.”

The school security working party was set up after the stabbing of London headteacher Philip Lawrence as he tried to protect a pupil from another teenager outside his school gate.

Welcoming the report of the school security working group, Education and Employment Secretary Gillian Shephard said the Government had amended the Offensive Weapons Bill to make it an offence to carry a knife or other offensive weapon on school premises and to extend police powers of search in schools.

Of the 22 per cent overall of pupils in the survey who claimed to carry weapons, 10 per cent did so only at school. Just over half carried them close to home, 11 per cent only in the street, and about 12 per cent took them everywhere.

Who carries what, and what can be done about it

Other key points from the Exeter report

* Asked if they ever “carried” anything to protect themselves, three-quarters of boys and 90 per cent of girls in Year 7 did not, compared with 66 per cent of boys and 79 per cent of girls in Year 11.

* A sound alarm was the most popular weapon with girls of all ages, followed by knives and defensive sprays. Each of these rated at just over six per cent with girls in the oldest age group.

* Knives were the weapons of choice with boys of all age groups, carried by over 15 per cent of those in Year 7 and peaking at 22 per cent of those in Year 10.

* Other weapons were almost as popular in Year 11: these included bats, poles, cues or other wooden items, chains or similar, knuckle-dusters or darts.

* The carrying of all kinds of guns also appears to peak among 14 and 15-year-old boys: 3.5 per cent claimed to carry a weapon firing air pellets, with a further 1.8 per cent saying they had a gun which fired bullets.

* Boys were increasingly likely to carry weapons as they got older, rising from a quarter of 11-year-olds to a third of 16-year-olds. This was less obvious from the girls’ answers.

National Union of Teachers’ survey on violence in schools: main findings * More than three in five schools vandalised by intruders in the past year;n Nearly one in 10 schools hit by arson;

* Intruders a common experience for one in 20 schools;

* Pupils in one in five schools assaulted by non-members of the school or adults connected with the school, usually during the day and close to the school;

* Staff assaulted by intruders in one in 10 schools during the working day and after school hours in more than one in 20 schools;

* Staff assaulted by adults connected by the school in 15 per cent of those contacted;

* Half the schools felt security was adequate, almost half thought it could be improved at reasonable cost and almost two-thirds had sought external advice on school security.

Working Group on School Security:

main recommendations

* The Government should make guidance available to schools, police and other agencies on powers available to the police and criminal justice system to deal with troublemakers in and around schools. It should also advise on good practice in local liaison between schools, police, and other agencies.

* The Government should review whether there is a need for further strengthening of the law.

* The Department for Education and Employment should publish guidance on improving the security of schools and designing more protection into new buildings.

* Schools should continue to review their security, particularly control of access.

* The Government should make substantial new money available as soon as possible from the Grants for Education Support and Training programme for improving school security, with parallel arrangements for grant-maintained schools.

* Governors should get more support to help them fulfil their security responsibilities.

* Teachers, support staff and governors should be given appropriate training.

Cash and Carry is available at Pounds 10 from the Schools Health Education Unit, Exeter University, Heavitree Road, Exeter EX1 2LU or telephone 01392 264722. School security: the report of the working group is available from the DFEE publications centre. Telephone 0171 510 0150 to order. A feature on security systems will appear in TES Resources Extra, May 31