FOND DU LAC -- Authorities at the state and local level are investigating a series of five fires in Fond du Lac County that happened March 19 and 20.
In a news release, the Fond du Lac County Sheriff's Office described the fires as "suspicious."
All of the fires took place within an area of approximately four square miles in a timeframe of approximately 30 hours.
Officials are still collecting evidence, but believe at least three of the fires were intentionally set. Residents in the area are encouraged to inspect the outside of their homes and report anything suspicious.
Anyone with information is asked to call the Wisconsin Arson Tip Line at 1-800-362-3005. Tipsters can remain anonymous and earn a reward of up to $5,000 if the tip results in an arrest or conviction.
Residents can also contact local law enforcement at 920-929-3390 and report anonymous tips at 920-906-4777.
Anyone who notices a suspicious person or circumstance in progress is asked to call 911.
The Fond du Lac County Sheriff's Office, Fond du Lac Police Department, North Fond du Lac Police Department and Wisconsin Department of Justice State Fire Marshal's Office are investigating the incidents.