"Have-a-go heroes" should be trained by police on how to confront anti-social behaviour and deal with aggression and conflict, a report has said.
A radical new approach to tackling anti-social behaviour is required if the problem is to be tackled, the Royal Society of Arts (RSA) report said.
Training should include self-protection and restraint, how to read a situation to appraise when it is appropriate to intervene or when to call the police, and skills in conflict resolution and mediation, it said.
Ben Rogers, the report's author, said: "With the real prospect of traditional police patrolling being scaled back, now is surely the time to focus seriously on agreeing the core skills that active citizens need - individually or collectively - if they're to step up to the mark.
"The coalition Government has signalled its determination to encourage and support citizens to 'have a go' and intervene to stop criminal behaviour.
"But to do this, citizens need training and the Government needs a strategy if these emerging ideas are to be supported and developed."
Police officers or "lay trainers" should provide the training for frontline public servants including park-keepers, public transport workers, street cleaners, parking enforcement officers, caretakers, teachers and other school staff, social workers, community and youth workers and neighbourhood managers, he said.
The report, First Aid Approaches To Managing Anti-Social Behaviour, also said training could be given to people who are "potentially influential within their communities", such as shopkeepers, publicans and postal workers.
Javed Khan, chief executive of Victim Support, said: "We don't want to create more victims by people taking unnecessary risks in 'have-a-go-hero' situations. The public should always put their safety first and rely on emergency services.
"But giving frontline public servants the skills to recognise when it's safe to intervene and the ability to help defuse potentially difficult situations is valuable if done appropriately. We are even involved in a local scheme that helps victims learn how to avoid problem situations from escalating."