Schools have fallen under siege by thieves and vandals with more than 20 break-ins recorded in the first three months of this year.
Rampaging yobs have smashed windows, sprayed graffiti and made offwith equipment in a spate of burglaries.
Thousands of pounds worth of damage has been caused to a string ofeducational buildings across North Wales.
Crime against schools sites is most rife in Wrexham, statistics released under the Freedom of Information Act show.
The news comes as pupils prepare to begin the new term next month.
North Wales Police list 21 school buildings struck by thieves between January 1 and March 31 this year.
Categorised as "burglary other than dwelling", the list includes six schools and colleges in Wrexham, three in Rhyl, two in Caernarfon,Flint and Bangor and one each in Colwyn Bay, Conwy, Bagillt, Anglesey, Chester and Deeside.
A police spokesman said: "The information supplied is not a reflection of the school, the pupils or the staff."
The shocking figures spurred a joint agency School watch clampdownwhich sees the force helicopter hover above buildings in a bid to slash the number of summer holiday break-ins.
Police say in one county alone, pounds 100,000 worth of damage wascaused to schools since 2005.
Last night, Wrexham Inspector Chris Beasley said operations and initiatives help to drive down crime.
"The security surrounding schools is an issue for schools and the council in the main but we help by increasing patrols when they are closed during holiday periods," he said.
"We certainly take any illegal activity on school premises very seriously and offenders are mainly of a very young age.
"We have an initiative in place called Operation Gingerbread wherewe increase our police presence with high visibility patrols to deter offenders.
"The scheme has been very effective and we have seen a drop in thenumber of burglaries reported - there has certainly been no serious offences committed this summer."
Since March, detectives have appealed for information about other burglaries committed across the region.
Last month, a large amount of cash was stolen from Mountain Lane School in Buckley.
In recent months two schools in Flint suffered smashed windows anddamage totalling pounds 1,000 was caused to Acton Park Junior and Infant schools in Wrexham after vandals went on a wrecking spree damaging 20 windows.
Neil Foden, head teacher at Ysgol Friars in Bangor said his schoolis targeted by thieves at least once a year.
He said: "People have broken into one of our canteens in our new conservatory but we have new CCTV systems and security link ups that have helped to catch or identify the culprits.
"In the last two attacks the perpetrators have been caught and prosecuted.
"In most cases, people have been trying to steal sweets and drinksand so our biggest problem tends to be the amount of damage caused rather than the value of what has been taken.
He added: "For repairs we are looking at three-figure sums and it really is demoralising.
"Our pupils take great pride in their school and don't want to seeit damaged or things taken."