Teachers have been forced to evacuate their classrooms after coming under attack from children as young as five.
Staff are regularly punched, kicked and bitten by unruly pupils, many of whom are still in primary school.
The extent of violence was laid bare as new figures revealed two attacks on teachers take place every week in Northern Ireland.
Ninety assaults were reported in the last year – however, teaching unions said these represent the tip of the iceberg.
Brendan Harron from the Irish National Teachers' Organisation said he had been told of several incidents where violent pupils had led to classrooms being evacuated.
"You are talking about pupils who are four or five years old," he said.
"I know of a P2 teacher in the last year whose classroom had to be evacuated – that's a five-year-old child."
More than 400 attacks on teachers have been reported in the past five years, including 90 in the last 12 months alone.
And the real figures are much higher because they do not include the Southern Education and Library Board – Northern Ireland's biggest education authority – or voluntary grammar and grant maintained integrated schools.
Nor do they take account of the many incidents which go unreported every year.
The figures were released by Education Minister John O'Dowd in response to an Assembly question from DUP MLA Peter Weir.
The issue of violence in the classroom has come under renewed focus following the murder of a teacher in England.
Ann Maguire was stabbed to death at Corpus Christi Catholic College in Leeds last month.
Mr O'Dowd said 90 attacks on teachers had been reported in the last 12 months – 34 in the South Eastern Board area, 32 in the Belfast Board, 15 in the North Eastern Board, and nine in the Western Board.
Mr Harron, whose union represents around 7,000 members in Northern Ireland, said violence in the classroom was a growing problem.
"Most of the calls we are getting are about primary school pupils," he added. "There has been a massive increase in the number of teachers asking for help – pupils biting other pupils or kicking the teacher. In some cases they are having to evacuate classrooms to bring under control a pupil who has just lost it."
Mr Harron said he knew of pregnant teachers who had been left terrified by their pupils.
"The big shift I have seen in recent years is towards primary school pupils," he added.
"We are getting 10 times as many calls from primary teachers about violent and disruptive pupils than we do from post-primary teachers."
The figures have remained broadly similar over the past five years, with 79 reported in 2009/10, 93 in 2011/12 and 90 last year.
When the Southern Board, voluntary grammar and grant maintained integrated schools are factored in, the number of attacks is likely to run well past 100.
Mr Weir, who obtained the figures, said he was very concerned.
"We are trying to encourage young people into the teaching profession, and this could be off-putting to many," he said. "The vast majority of teachers will go through their careers without any problems, but we need to ensure we have sufficient discipline within our system.
"It isn't simply a question of disruptive pupils, but where they have been physically violent to teachers, and they need to be dealt with in a very clear manner."
Mr O'Dowd said his department was working with the PSNI on the issue.
"Assaults on teachers, or any other staff in schools, whether physical, verbal, written or electronic are intolerable, totally unacceptable and must be condemned," he said.
"All the key stakeholders in education must work together and stand together against any abuse or violence directed at the workforce.
"My department will continue to work with the employing authorities and teachers unions to explore ways of preventing violence and abuse against teachers and support staff who are subjected to it.
"The department will also continue to co-operate fully with the police with regard to any advice and recommendations about the protection of teachers and school staff."
Belfast principal knocked out by relative of a pupil
A BELFAST principal was punched in the face and knocked out by a relative of a pupil.
Police and an ambulance crew were called after the headmaster, a teacher for more than 36 years, fell to the ground unconscious in 2008.
The teacher said he was “disgusted” by the attack, adding that it raised important issues about the safety of teachers.
“It was quite a shock. I was very surprised and disgusted with the whole thing.
“I am not marked, there was no physical damage as such,” he said.
“This is something that shouldn't happen in any school.
“It is unfortunate that this sort of a situation was created where there are children. What sort of a message is it giving them?”
Staff's three-week strike after colleague assaulted
AN assault on a teacher at Movilla High School in Newtownards led to a strike by staff lasting three weeks.
The school’s 450 pupils were unable to attend classes after teachers took industrial action because employers docked their pay when they refused to teach the pupil said to be responsible.
The incident in 2008 began when the boy and another pupil arrived 15 minutes late for a class. The teacher said they would have to stay behind and make up their time. The boy got up to leave at the end of the class and the teacher blocked his way with his arm. The boy pushed his arm aside and walked out.
Jail for blackmailing student who threatened pregnant victim
A STRAIGHT-A student was jailed after threatening her teacher's unborn baby and blackmailing her into sending sexually explicit pictures.
Amie Danby was sentenced to a year in custody after a judge said her threats were “quite outrageous” and “disgraceful”.
A-Level student Danby (19), from West Link in Holywood, adopted various identities to demand that the teacher send explicit photographs and text messages. Danby also threatened her victim with paramilitaries if she didn't comply, and used several aliases when contacting her.
Such was the level of fear the female teacher was subjected to, she acquiesced, and even handed over £5,000 to Danby.
The judge said the extortion plot had been “pre-planned and persistent”, leaving her victim suffering mental torture.
' Hit with furniture, chased, slapped and spat on... it just goes with the job now’
A TEACHER described how he was left with whiplash after being attacked by a pupil.
The man, from Co Antrim, has lost count of the number of times he has been attacked in a career spanning many years.
In one particular incident the violence escalated, leading to an attack which left him off work for months.
“This pupil had been trying to bite me, slap people, hit me with furniture, tried to choke me and then it escalated,” he said. “I was hit in the leg with a missile and then the head.
“I've been teaching for decades and I always liked working with children with difficulties. All children are entitled to an education, including those with challenging behaviour.
“In the past I've been hit, thumped, kicked, spat at, chased, pushed up against a wall — I've lost count of the number of attacks. It just goes with the job. I got into teaching as I wanted to help.
“I believe the child who attacked me should have been given one-to-one teaching, but there isn't the money for it; so I got hurt.”
He said there was a lack of respect for teachers nowadays.
“Parents used to have a big respect for teachers but that has changed.”