An early morning that appears to have been deliberately set has caused extensive damage to Sunshine Hills Elementary in Delta, B.C.

Delta Fire and Rescue Services' Battalion Chief Mike Richardson said that a call came in before 2 a.m. PT, reporting a fire outside the school, up against the side of the building.

Delta Fire and Rescue Services' Battalion Chief Mike Richardson says the blaze began at the back of the school, and appears to have been deliberately set. (CBC)

"The unfortunate part is it was set so that it spread into the school and ended up doing quite significant damage to the school," he said. "It's been a nasty fire to put out because it gets inside the plenum, and it works its way along and we can't gain access to the plenum."

Six trucks in total responded to the school, located at 11285 Bond Blvd.

In addition to fighting the fire from the inside of the school, firefighters also used saws to cut through the metal roof. More crews would be coming in to strip the walls off to gain access to all the spaces and make sure the fire is out, Richardson said.

The battalion chief said fire investigators have not begun their work, but he's fairly certain the cause of the fire is clear.

Firefighters cut into the school's metal roof in order to access all areas where they fire may have spread. (CBC)

"I would suspect arson in this case," he said. "It definitely had some logs or something put up against the building."

Delta police were already at the scene, gathering information to help locate one or more suspects.

No one is reported to have been injured in the fire.

"The crews are all safe, but tired. It was a tough fire to put out," Richardson said.