Breach of the peace
This is committed when an individual causes harm, or appears likely to cause harm, to a person, or in that person’s presence, to his/her property, or puts that person in fear of such harm being done through an assault, affray, a riot, unlawful assembly or other disturbance.
The basic principle is that a police officer may take reasonable action including arrest to stop a breach of the peace which is occurring, or to prevent one which the police officer reasonably anticipates will occur imminently. Reasonable action may also be taken where a breach of the peace has been committed and it is reasonably believed a recurrence of the breach is threatened.