(NewsNation) — Portland police are investigating how at least 15 police vehicles caught fire Thursday morning at the department’s training division.

Officers responded at 1:55 a.m. to the Portland Police Training Division and found the vehicles ablaze in a fenced area, according to a news release.

Firefighters extinguished the flames and there were no injuries. The building on the property was undamaged.

Police are asking anyone with information about the situation to contact the department at Meredith.Hopper@police@portlandoregon.gov or call the fire department’s investigation unit’s tip line at 503-823-3473.