Police said the blaze that gutted two classrooms was being treated as "possibly suspicious".

A large blaze that gutted two classrooms in Green Bay Primary School in West Auckland is being treated as possibly suspicious.

A Fire and Emergency spokesman said five crews were called to the blaze, which broke out before 4:40am on Sunday.

The fire was largely put out about an hour later and crews had left the scene by 9:30am.

JASON DORDAY/STUFF Five fire crews battled a blaze at Green Bay Primary School in West Auckland on Saturday morning.

A fire investigator was called to determine the cause of the blaze.

Police said they would like to hear from anyone who was in the Godley Rd area around 9pm on Saturday and remembers seeing anything suspicious.

"We encourage anyone who may know something about the fire to get in touch with us, we just want to understand what happened," said Detective Sergeant Kelly Farrant, of the Waitemata Police.

NZ POLICE Police wanted to hear from anyone who might recognise this push scooter

She said police would also like to hear from anyone who may recognise two scooters, one with blue details, on with pink details.

A Fire and Emergency spokesman initially said the fire was not being treated as suspicious, however, police said later on Sunday afternoon it was "unexplained" and being treated as "possibly suspicious".

"As a result of the fire more than 60 children have now been displaced from their classroom, and have lost valuable mementos and work," Farrant said.

NZ POLICE A police detective said it was disappointing the children lost their mementos.

"The classroom is only a little over a year old, and it's disappointing for the school and the children to end the year on a low note."

The school's Board of Trustees chairwoman Amelia Day said the next few days would be about making sure the wellbeing of students, staff and community was looked after.

Information could be given to local police stations, or to Crimestoppers, anonymously on 0800 555 111.

NZ POLICE A scooter with pink details was also an object of investigation for police

JASON DORDAY/STUFF The fire gutted two classrooms of the primary school.