Increasing classroom violence has victimised about a third of teachers in Britain, according to a new survey.
Over half of the teachers surveyed said that their school's policy regarding pupils' poor behaviour was not tough enough.
Two thirds even said that they had contemplated quitting their profession due to the rise in physical aggression, verbal abuse, and threats in the classroom.
Issued by the Association of Teachers and Lecturers, the survey's findings suggest that excluding the most violent youngsters does not help because they will repeat the pattern of violence at neighbouring schools.
Union's General Secretary Mary Bousted believes that teachers should not have to put up with the violent behaviour seen in schools these days.
"Not only is poor behaviour driving teaching staff away at an alarming rate, it is also damaging the chances of other pupils during lessons by causing major disruptions," Times Online quoted her as saying, while addressing the union's annual conference in Torquay.
She said that one in ten teachers had suffered physical injuries in the classroom.
While 12 per cent of the teachers said that they had to visit a doctor, eight per cent had taken leave from teaching as a result of pupils' aggression.
Three per cent of the teachers surveyed reported being a victim of incidents involving knives, while two thirds said they had been punched. Nearly a half had been kicked, and a third threatened.
The survey, which follows news last month that airport-style metal detectors are to be installed at hundreds of school gates, also revealed that pupil behaviour had worsened in the last two years.
Most of the teachers surveyed said that low-level disruption like pupils talking, not paying attention, or refusing requests to turn off mobile phones had become the norm in classrooms.