Police are investigating a suspicious fire at a Wainuiomata primary school.

Emergency services were called to the blaze at Pukeatua Primary School in Wainuiomata about 4pm Saturday, Detective Sergeant Scott Cooper, of Lower Hutt police, said.

Fire crews arrived to find the outside decking and one of the classrooms fully engulfed in flames.

The fire was brought under control before it could spread to other areas of the school, Cooper said.

Fire investigators and police said the blaze appeared to be deliberately lit.

via TVNZ