Honolulu police have opened a first-degree arson investigation into a dumpster fire that damaged part of Mililani Uka Elementary School.

Police said there were no arrests as of Sunday afternoon.

Honolulu Fire Department Capt. Scot Seguirant said 14 firefighters responded to the fire at 94-380 Kuahelani Ave. at 5:03 p.m. Saturday and found smoke and flames from the dumpster burning up the outer wall and to the eaves of the school’s cafeteria.

Firefighters extinguished the flames within six minutes of their arrival. The building was closed at the time and no one was inside. There were no injuries.

Damage was mainly confined to the outside of the building, but some smoke and heat damage was found in the cafeteria washroom, Seguirant said.

Firefighters determined the fire was intentionally set and handed the investigation over to police, he said.

An estimate for the fire damage was pending.