Loitering Vic sex offenders caught

Children need the confidence to speak up when they feel uncomfortable, police say, after 35 Victorian sex offenders were caught loitering near schools and in public places.

Crime Statistics Agency figures show 35 sex offenders were caught loitering in the year to September 2015, up from 29 in the previous year and 19 the year before.

The figure was still down on the 2011-12 number, when 62 known or convicted sex offenders were caught loitering near schools or in public places.

Superintendent David Watt said parents should encourage their children to speak up when they were uncomfortable about what a stranger or someone they knew had done.

"(It's important) to know when they're feeling uncomfortable and it's absolutely okay to speak up about that and to tell someone and that people will believe them and they will do something," Supt Watt told AAP on Monday.

"That's one of the greatest tools these perpetrators have, is that they're able to control children in a way that they will not report that sort of behaviour."

Supt Watt said Victoria monitored serious sex offenders living in the community to ensure they were meeting the conditions of their releases.

"We focus our resources on the most serious sex offenders that we believe are more likely to re-offend," he said.

Supt Watt encouraged parents to call 000 if someone was behaving strangely around their children.

"If it's unusual, if it doesn't sit right with you, then ring triple zero," he said.

"That's not to say that an offence needs to have been committed.

"But if it looks unusual to you, then maybe it is unusual."

Supt Watt stressed that more than 90 per cent of child sex offences were committed by someone known to the child.