Colleges in the capital have drawn up plans to tackle youth gangs after one in eight of them said they had students affected by murders.
A report by the London region of the Association of Colleges said 88 per cent of the survey respondents disclosed concerns about gangs, after a year in which 29 young people died violently and 171 gangs were identified by police.
While colleges say that an overwhelming majority of students are not involved in gangs, many live in areas where they are a problem. More than half the colleges have had to deal with students carrying and occasionally using weapons, the survey found.
In collating their experiences, the 53 London colleges intend to offer potential solutions to others across the country that encounter problems with youth gangs.
Sue Rimmer, principal of South Thames College and chair of the AoC London region, said: "For many of our students, colleges provide them with a way out of some of the problems of their communities, access to a meaningful course and an alternative future.
"We are not just large training providers: we are right in our communities and an important part of their cohesion."
Some colleges had students involved in or affected by murders, although none were on college premises. Not all were gang related.
But colleges also had to deal with harassment or threats when students brought acquaintances on to the site for protection or to threaten others, and petty criminal activity.
Some reported that students had dropped out after seeing gang members in college, or that attendance had been affected by students taking long routes to avoid trouble spots, or groups of students dominating facilities and trying to create no-go areas in college.
However, three-quarters of colleges said campuses were regarded as safe places: student feedback reported college was often the safest, least disrupted part of their lives.
Colleges said the gangs were usually territorial and male. Some said mainly younger students are involved. Some reported a seasonal cycle of activity: there was more in the first part of the college year, with violence more likely in the dark, winter months.
Ms Rimmer said: "For us, it is important to recognise the challenges that our young people face and to listen to them. They're not only aware of the issues but they have strong ideas on how they can be dealt with."
After one stabbing, the College of North East London brought together Turkish, Kurdish and black students to build understanding in a project seen as a pioneer by the Metropolitan Police. Students have now been on theatre trips together.
The colleges felt there needed to be clearer guidance on when exclusion might be necessary and how to ensure that a student's prospects are not permanently damaged.
One college uses distance learning for violent or disruptive students, only allowing them on site when escorted. Others suggest that a system of managed referrals between colleges, as happens in schools, should be developed.
Relationships between security staff and students can help students act more responsibly, colleges found: West Thames College even uses them as mentors.
But while security technology was effective, staff said it was impossible to keep out all potential weapons, when belts, sticks and bottles had all been used in assaults.
Editorial, page 6
`Tackling and Preventing Gang Problems in London Colleges', www.aoc.co.ukenaoc_regionsAoC_Londongangs.cfm.