Fake money was discovered in Presque Isle County in the past week.

The Rogers City Police Department received a counterfeit $100 bill that had been put into circulation in the city, and a man brought several other fake $100 bills into the Presque Isle County Sheriff’s Office, saying he had found them on the highway, according to Det. Joseph Mulka of the Sheriff’s Office.

The bills, which are otherwise realistic, have a slightly different feel from standard money and are marked with pink Chinese characters on both sides. The U.S. Secret Service has verified that the bills, which all bear the same serial number, have been discovered in other cities across the country. Police currently have no suspects, but the case is under investigation.

Counterfeit $10 bills were also discovered in Presque Isle County in spring, the first such incident in Mulka’s memory since 2010.