HALIFAX -- Police in Cape Breton are investigating three fires that happened at Parks Canada sites, including a large one that destroyed a canteen and washroom facility at Ingonish Beach in Cape Breton Highlands National Park.

Fire crews responded to the fire at the Ingonish Beach Day Use Area early Saturday morning.

The building, used by hundreds during the summer, had been shuttered for the winter season.

Fire crews say three charred propane tanks were found behind the building.

They are treating the fire as suspicious, and believe it started in the women's washroom.

“The call came in at 6:57 a.m. When we arrived, it was already fully engulfed, there was hardly anything left. There were three 500-lbs propane tanks that were on fire at the time that we arrived,” said Chief Ervin Barron, with the Ingonish Beach Volunteer Fire Department.

“It was just a matter of keeping them cooled down. The rest of the building was gone.”

In an email to CTV News, a spokesperson for Parks Canada said there was also two incidents of small fires in washroom and privies at Warren Lake and Black Brook.

No injuries were reported in any of the three fires, and the investigation for all of them continues.