Emergency services were called to the incident at 1.20am on Saturday when four of the classrooms and another significant building were found alight.  Country Fire Authority firefighters were still on the scene this morning.

Police and fire investigators attended the school on Saturday afternoon.

Ararat Rural City mayor Paul Hooper said up to 150 students would be affected by the damage. 

“I’ve been on site speaking to parents, teachers and other people with a connection to the school and everyone’s pretty flat,” Cr Hooper said. 

“There will be a significant inconvenience for all of the students of the school but Ararat is a unique place because in circumstances of hardship we band together and help each other out because we're a strong and resilient community.”

Cr Hooper said discussions would begin with the Education Department in coming days to find replacement portable classrooms, while the option of engaging the town’s three other primary schools was also being explored. 

In a statement CFA operations manager Bernie Fradd said about 50 firefighters including some from Ballarat City took part in the effort to contain the fire. 

“The brigades did an excellent job ensuring the fire did not spread beyond the wing involved,” Mr Fradd said. 

“Ambulance Victoria was in attendance for health monitoring due to the fairly intense nature of the firefight.

“Ararat Fire Brigade will be on scene until lunch time today mopping up.

“The cause of the fire is not known at this stage, Fire Investigators will be attending this morning."