A teacher who had a knife pulled on him by a pupil says classroom behaviour is at its worst in his 20 years of teaching.
It comes as teaching union, NASUWT, says some of their members are worried about going to work as a result of a "serious increase" in poor learning behaviour in recent years.
Latest annual figures show school exclusions have hit record levels in Wales across all measures.
The Welsh government said any form of violence or abuse against staff or pupils was "completely unacceptable" and they were looking at proposals to improve behaviour.