The classroom knife attack on Avondale College teacher David Warren today took place ahead of a summit to be held in Wellington later this month to address school violence.
Ministry of Education representatives, police, principals and community groups - who all agree current legislation does not deal with the problem - are due to meet on March 16 and 17.
According to Frances Nelson, president of the New Zealand Educational Institute representing 48,000 primary and early childhood teachers, schoolchildren have become more violent in recent years.
"It's about the increase in the type of violence, the number of incidents and perceived threat to the teachers, other staff and students," Ms Nelson said.
Police have said they are being regularly called to schools throughout the academic year to deal with behaviour teachers cannot handle.
Figures released to The New Zealand Herald under the Official Information Act show officers made an average of 1531 apprehensions each year from 1998 to deal with violence, drugs or sex offences at schools and universities. Last year, they made 1658 apprehensions, averaging 32 a week.
The number of calls over violent offences jumped 27 per cent in the past decade - from 869 to 1064.
Total school enrolments rose only 4 percent from 2001 to 2009 and education sector lobbyists have warned the rise in offences is alarming.
Education Minister Anne Tolley said today's stabbing of Mr Warren - when he turned his back on the class to write on a whiteboard - was "quite unusual".
"But the general levels of violence in the community are growing, and perhaps the level of violence in schools reflects that."
She told Radio New Zealand that the summit meeting in Wellington was intended to share good practices that had been developed in schools.
"I think the summit will give us an opportunity to explore what is effective and what are the priorities for further action."
Ms Tolley said numbers of violent offences by students against other students had been relatively stable over the past five years, and there had only been a small increase in attacks on teachers.
Prime Minister John Key told NZPA that he was "very alarmed" that a teacher had become a victim of violent crime. "Clearly it's unacceptable behaviour.
"But we need to understand whether it's an isolated incident out of left field or whether something a bit more serious is going on."
The Wellington talks will consider whether suspending and standing down students is needed to deflate violent situations.
Bob McCoskrie, national director of the Family First lobby group, said recently he was concerned schools were discouraged from suspending or standing down their students but were encouraged to bring in police officers fulltime.
Manurewa High School has had a police officer on-site for nine years, following the introduction of a government scheme to put police in 10 low-decile secondary schools.
The school also employed three social workers, two guidance counsellors, three nurses, a youth worker, a truancy officer and an attendance officer.
