A large fire broke out in the woodwork classroom at Whangamata Area School this morning.
The woodwork room caught on fire about 11am and fire fighters were still bringing it under control an hour later, north fire communications shift commander Scott Osmond said.
Six fire trucks from Whangamata, Waihi and Pauanui were battling the blaze.
Today was the co-ed school's athletics day so most students were already out on the fields, an office staff member said.
The woodwork room was understood to have been locked at the time and no one was believed to have been inside when the fire started, she said.
No one was injured.
The fire was under control and the smoke was starting to dissipate, she said.
The school was in the process of sending students home with their parents who were at the school to watch the athletics day or contacting their parents to ask them to pick their children up.
Whangamata Area School covers children in Year 1 through to Year 13. There are over 420 students.