A stern warning has been issued by police this week following acts of mindless vandalism in the grounds of Saundersfoot School.
Abusive graffiti has been placed on the walls, wooden benches have been defaced with carvings and there is evidence of a small fire having been set.
On one occasion during the Easter holidays, when several reports about the vandalism were made to police, youths were seen skate-boarding on the school roof.
"Perpetrators of these acts are reminded that these incidents are criminal and they will be dealt with accordingly," warned PC 601 Mike Smith, of Saundersfoot police station.
"Parents are asked to bring this problem to the attention of their siblings who are of an age where they might become embroiled in like situations," continued the officer.
"The fabric of the school is expensive to maintain and the cost of which is borne by the school budget," he explained.
"Incidents of this kind also reflect badly on the health of the community in which the school partakes.
"It is an offence to be on school property without authority," PC Smith pointed out.
Members of the public are encouraged to contact the police immediately should they see persons on school property out of normal hours.