A fire this morning at Russley School in Christchurch has forced its closure.
The school's PTA confirmed on Facebook that rooms 1 to 4 were damaged.
Principal Greg Lewis told 1 NEWS the blaze affected about 120 students who use the Year 7 and 8 block. The school's current roll is about 470.
"It's a quarter of our school, really," Mr Lewis said.
"We're just going to look to make a plan over the course of the day, try and get things secure and most importantly probably try and look after our people. Four teachers have lost classrooms, kids have lost a whole bunch of stuff, so that's really our concern."
Mr Lewis said the community was being made aware there was no school today, and he would now be looking into what space they have available.
"In the immediate, we have a couple of hall spaces that are available - that might be a plan. But then we've got to sort out a whole bunch of other stuff that supports that as well - we've got no gear from those rooms now.
"Busy day, we'll see how we go."
Fire and Emergency New Zealand said several calls were made about a fire at the school at 7.10am today. There are four crews and a command unit at the scene.
Christchurch City Fire Station senior station officer Mark Elstone told 1 NEWS on arrival two classrooms were well-ablaze and another two had significant damage. An admin block also had smoke damage.
The fire covered a total of 600 square metres but is now extinguished.
Mr Elstone said firefighters' concerns were with those of the school, but added there was a member of the Ministry of Education on site liaising with school representatives.
"It's only four classrooms but for those classes that operate out of there, it's a big blow. It's a major blow for the school."
The cause of the fire is unknown, but conveniently, fire investigators were on their way into town when it happened. They followed the fire trucks so they are now on the scene and will be carrying out investigations today to determine what caused the blaze.