FOND DU LAC, Wis. (AP) — A series of fires in Fond du Lac County over the last week has spurred a search for a suspected arsonist.

WBAY-TV reported Saturday that five fires have broken out in Fond du Lac and North Fond du Lack since Thursday. Four of the fires occurred within hours of each other on Friday morning.

Authorities said at least three of the fires appear to have been set intentionally.

Deputies from the Fond du Lac County Sheriff’s Office and police officers from Fond du Lac and North Fond du Lac are working with agents from the state Department of Justice State Fire Marshall Office on the investigation.