Port Huron businesses and individuals are advised to be vigilant after five St. Clair County locations received counterfeit bills last weekend. According to the St. Clair County Sheriff’s Office, businesses around Port Huron Township, Marysville, and Fort Gratiot Township reported getting $100 bills last week that the offenders exchanged for real money. A liquor store, Menards, and AutoZone were all victims, but officials say other companies may have received the bills but had not realized they were fake. The suspects are believed to be three black females who were in a white Kia Forte with a Florida license plate. Anyone with more information should contact the St. Clair County Sheriff Department at (810) 985-8115.