A LAUNCESTON state school must pay more than $3000 to repair more than a dozen vandalised windows.
Prospect High School principal Cary Stocks said the smashed windows were a "senseless act" and the money would have otherwise gone towards student resources.
The vandalism greeted grounds keepers and Mr Stocks when they arrived at work on Monday morning for the new school term.
Vandals had smashed more than a dozen windows across three buildings: the materials, design and technology block, as well as the science and music block.
The affected buildings were in the southern area or rear of the school grounds.
Mr Stocks said the vandalism occurred some time between the Launceston public holiday on Thursday and Monday morning.
But he said the weekend was the most likely time.
A vandal also smashed another school window overnight between Monday and yesterday.
Mr Stocks said the vandalism was very disappointing.
"It requires a lot of time and effort to clean that up," he said.
"That came down to our education facility staff getting those rooms safe and ready for learning.
"It did not really affect students.
"We were able to get that sorted in time."
The school has been the victim of vandalism in the past, including graffitied signs and smashed windows.
Mr Stocks said the damage bill, estimated at more than $3000, was "fairly substantial" and could have been spent on student resources.
"We seem to get a fair bit of vandalism out of hours," he said.
"It's just very frustrating because it's taking resources away from other things.'
Police urge anyone with information about the smashed windows to call Launceston Police Headquarters on 6336 3701 or Crime Stoppers on 1800 333 000.