Figures obtained by The Sunday Age have painted a troubling picture of the issues plaguing the system, revealing almost 6000 reports in the past three years that have required intervention from the Education Department.

Among the data, 506 assaults were recorded in 2011-13, along with 3049 burglaries, 125 drug-related allegations, 439 sexual assaults and 13 deaths.

Many take place on school grounds - classrooms are easy targets for computer thefts, and there have been various assaults, including an attack on an eight-year-old girl at Glenferrie Primary School two weeks ago.

But the government insists that none of the 13 fatalities occurred on-site, pointing out that principals are encouraged to report cases even if they take place outside school hours, if they involve students or staff.

Education Minister Martin Dixon said: ''This data highlights the important role our schools play in their community to ensure that issues involving school-age children are reported, regardless of whether they happen off or on-campus, and students get the support they need.''

The figures were obtained under freedom-of-information laws, but despite requests the department

declined to provide specific details of every death reported. Instead, spokesman Stuart Teather highlighted three examples on the public record that were linked to schools: the bludgeoning of 11-year-old Luke Batty by his father (welfare support was provided for students who knew Luke); the brutal stabbing in Sunshine of Melbourne mother Fiona Warzywoda, allegedly by her de facto partner (Ms Warzywoda had school-age children); and the death of a 25-year-old man in Horsham who was bashed by six adults in 2012 (support was given to students at a local school who knew the victim).

Principals warn the figures could be the tip of the iceberg, because some schools now believe the department is stretched too thin to tackle their problems efficiently and therefore they don't report every incident.

Australian Principals Federation president Chris Cotching said: ''Some people have lost faith in the system being able to respond to emergencies in a timely manner, so they can't be bothered reporting.''

The statistics come amid growing concerns that schools increasingly are being asked to deal with complex social welfare issues as community and parental expectations rise.

Australian Education Union state president Meredith Peace said that while difficult issues sometimes occurred, ''what's really important is that, if and when they do occur, there is appropriate support available''.

That was not always the case, she said. ''The cutbacks to regional [department] officers across the state has had a huge impact in terms of the level of support schools have had. There's often no one on the phone when schools call in because staff numbers have been cut so drastically, which leaves schools feeling like they're alone.''

The data also shows:

■ 5866 incidents reported since the Napthine government came to office, with most in the south-east and south-west of the state.

■ Since 2011, schools have reported 67 cases involving trespass or a breach of an intervention order; 129 fires; and 1043 cases involving property damage or vandalism.

■ The number of incidents reported has declined slightly each year, with 2141 cases reported in 2011; 1913 recorded in 2012; and 1812 in 2013.

Mr Teather said that given Victoria had more than 1530 government schools with almost 550,000 students, the figures suggested emergency incidents were rare.

Parents Victoria spokeswoman Gail McHardy said she hoped all schools reported problems in order to trigger the appropriate support, while opposition education spokesman James Merlino said the ''alarming figures should stand as a wake-up call to the Napthine government on the importance of investing in education''.

- The Age