Victorian schools are being forced to beef up security amid figures showing thousands of violent attacks and thefts are reported each year.

Government data shows that over the past three years, schools reported 4077 burglaries, 2598 cases of vandalism and 1880 alleged assaults involving teachers, parents or students.

The figures have prompted concerns about safety in schools, with some principals wanting more resources to pay for closed-circuit television cameras or security guards, while the Opposition has called for tougher penalties for school-based crimes.

Education Minister Bronwyn Pike said she believed schools were safe, but ''from time to time there are unacceptable incidents that we have to deal with proactively''.

Ms Pike's department has spent the past few years boosting alarm systems, which now operate in 95 per cent of Victoria's 1600 public schools. The department has also worked with police and security operators to ensure a rapid response when the alarms are activated. And it is updating its bullying policy for schools.

''We take these matters pretty seriously, and there's a culture of non-acceptance when it comes to bullying and aggressive behaviour in our schools,'' Ms Pike said.

But Opposition education spokesman Martin Dixon said this wasn't enough, and called for tougher penalties for crimes that were committed on school grounds or against staff and students. He said: ''There's been an alarming increase in the breadth and depth of crime in schools. I think the community has a high expectation that schools are safe places, but that perception is being seriously dented.''

The department's data reflects the reporting of burglaries, assaults and vandalism, meaning some reports may not be substantiated, or have occurred outside the school or out of school hours. The figures show 659 assaults were reported to the department during 2008-09, up from 538 in 2007-08. Burglary is also on the rise (1388 reports in 2008-09, compared with 1361 the previous year) and vandalism increased (856, compared with 836 the year before).

Some of the attacks may have happened between students, but others could relate to abuse in the home that was also reported. Another concern is the trend of teachers being abused by irate parents.

''Sometimes there are cases of parents who are passionate and obviously care about the welfare of their children, but don't always have the necessary skills to deal with issues and can sometimes get a bit confrontational,'' said Bendigo Senior Secondary College principal Dale Pearce.

Principal of Copperfield College in Melbourne's west, Tony Simpson, called for department funding to help schools pay for extra security. Special fund-raising efforts have enabled his school to install CCTV cameras and hire security patrollers. Many other schools are taking similar action.

Victorian Principals Association president Gabrielle Leigh said violence in schools represented a broader community trend, and highlighted the need for every primary school to have at least one welfare officer to help students deal with challenges they may be facing.