Authorities in Oregon are investigating a possible arson after 15 Portland Police Department vehicles were found burning early Thursday.

Portland Police said they responded to the Portland Police Training Division on 14900 block of Northeast Airport Way to assist Portland Fire and Rescue firefighters responding to a reported fire. Officers arrived to find at least 15 vehicles burning inside a fenced training area.

"The building was undamaged, and no injuries were reported," police said. The fires were extinguished.

The Portland Fire Investigations Unit, which includes fire investigators from Portland Fire and Rescue who are sworn law enforcement officers as well as a Portland Police detective, responded to the scene to investigate possible arson.

Police are asking anyone with information to come forward or submit an anonymous tip.

--with reporting by TMX