In February a teacher at Melrose High School was treated by ambulance officers after being shocked but no faults were found in the oven the teacher had been using, according to an Education and Training Directorate summary of the incident. A student at a Tuggeranong school received an electric shock in May this year, although the department has not revealed which school. Later it was revealed the device the student was using had been tested but had no test tag attached.

The internal documents describe so-called ''critical incidents'' at ACT schools. Critical incidents cover a wide range of issues including medical emergencies, accidents, intruders, violence and precautionary measures such as lockdowns.

Education Minister Chris Bourke said he was pleased with the fact there had been 41 incidents last financial year, compared with 37 in the previous 12 months.

''A review of critical incidents at ACT public schools shows reports have remained relatively stable over a two-year cycle, despite an increase in enrolments,'' Mr Bourke said.

''Each day, more than 40,000 students attend ACT public schools.''

One of the worst incidents in the past year involved the alleged abduction of a primary school pupil.

Police were called after an alleged abduction of a student near Arawang Primary School in May last year. Staff were asked to be extra vigilant following the incident and more staff were put on playground duty.

In July last year, students at Florey Primary School were disrupted when two unknown males, who may have been armed, ran across the public oval.

A teacher was told the men had tried to rob a nearby shop and students were ushered to a safer area.

Also in May last year, Wanniassa School went into lockdown for 20 minutes after one student had a violent outburst.

In July this year, police were told about a student at Lanyon High School continually lighting fires in school rubbish bins.

There have also been a number of teachers assaulted by students.

Police were contacted when one University of Canberra Senior Secondary College Lake Ginninderra teacher was assaulted by a student in March this year.

At least twice in the second half of 2011, teachers were put into the line of fire while trying to break up fights.

On one occasion, a Telopea Park School teacher was trying to stop a dispute between students which sent the school into lockdown.

The incident in May last year was bad enough to prompt the school to offer counselling to any witnesses.

In August last year, teachers escaped injury after stepping in to stop violence at Lyneham High School.

Incidents in non-government schools are not reported.