Honolulu police arson detectives have opened an investigation into a fire set outside of a classroom at  Waimanalo Elementary School Sunday night.

Firefighters responded at 7:30 p.m. to what was initially reported as a rubbish fire at 41-1330 Kalanianaole Highway. They found that a small fire had burned the door of a classroom. Police said people attending a meeting at the school put out the fire.

Fire investigators later determined that fire was intentionally set and turned the matter over to police. Damage was estimated at over $500.