A teenager has been arrested after he allegedly broke into a high school and set one of its buildings on fire, gleefully filming the incident and posting the footage online.

Residents of the central-western NSW town of Cowra, 110km southwest of Bathurst, woke to the news they would not be able to send their kids to school on Tuesday morning after a fire ripped through their local high school’s administration block.

NSW Police said emergency services were called to Cowra High School after 7.10pm on Monday after “extensive damage” was caused to the admin block by a fire.

“Fire and Rescue NSW extinguished the fire … smoke damage was also sustained to other buildings within the school grounds. There were no reports of any injuries,” police said.

Officers arrived at a home in Cowra just after 10pm, and arrested a 17-year-old boy.

“It is alleged the boy broke into the premises, lighting the fire, before filming the incident and uploading the footage to a social media platform,” police said.

In footage posted online by the Junee Bulletin, a person says “see boys, look at that sh*t burn”, as a fire burns in a nearby doorway.

The camera then turns towards signs that say “Administration” and “Visitors must report to the main office”.

“Administration office, look at that b*tch burn,” the person filming says.

In a separate video, the same person tells somebody how they managed to enter the building.

“They left the whole f**king back part on the top open, right on A block, so we just climbed up on the second floor and then we f**king went in,” he said.

“And them sliding doors, you can pull right open, and that’s what we did, and then we just lit the packages they had sitting there.”

The boy was charged with damaging property with fire, breaking and entering and disseminating footage of the incident.

In a letter to parents, Cowra High School principal Anthony Hamer said the “unexpected” incident would mean students would have to attend school remotely on Tuesday.

“This fire has caused damage to some areas of the school, and we are currently working to have the entire school site safe for the return of our staff and students,” Mr Hamer said.

“The safety of our school community is our No.1 priority and for this reason our school will revert to learning from home tomorrow for all students.”

The school remains closed, and the boy will face court on Tuesday.