St. Clair Police Chief Bill Hammack urged local residents to be on the lookout for counterfeit bills after four were passed at area service stations over the weekend.

Hammack told The Missourian on Monday that the four $20s were exchanged at FastLane near the Interstate 44-Highway 47 intersection, at the Phillips 66 One Stop on Gravois Avenue and at Casey’s General Store on North Commercial Avenue. Two of the bills were passed at Casey’s while one was passed at the other locations.

All of the fake money was passed sometime on Friday, Saturday or Sunday, Hammack said.

The chief said employees at two of the convenience stores discovered the counterfeit money when they balanced drawers at the end of a shift and not during the time the transactions took place when the fake bills were used. A local bank found the additional counterfeit $20 after a deposit was made.

Hammack said each incident is being investigated, and he hopes to view surveillance video at each scene.

He also said anyone who sees a counterfeit bill should contact the police department at 636-629-1313.