Upper Hutt's mayor says the suspected arson of a local college is impacting the whole community

Police are investigating a suspicious fire at Upper Hutt College that destroyed three classrooms on Sunday night.

The school's still closed as the fire exposed asbestos, making the area unsafe.

Mayor Wayne Guppy says people are disappointed and angry.

He says he spoke to the principal and young students staring at the damage, knowing it was part of them that'd been affected.