Salisbury Police are investigating 10 cases of counterfeit bills being distributed in Salisbury -- from Dec. 15 to Dec. 17 -- and have been in contact with the Secret Service.

Police said bills have been found in convenience stores and retail establishments.

Bills in denominations of $20, $50 and $1 pass at local businesses have been identified as having serial numbers KB25356823B, MB54412485C, MA82495055A, HF36431632B, JB253356823D and MF01442192A.

Someone also attempted to pass a fake $100 bill at a local business, police said, but printed on the bill were the words “For Motion Picture Use Only.”

These bills are typically used as prop money in movie, television or stage productions, police said.

A variety of purchases have been attempted for gift cards, money orders, car washing services and food. Suspects have also attempted to change larger bills for smaller denominations, police said.

Police recommend residents and business owners examine security markings on currency and compare them to other bills.

Those who receive suspicious bills should obtain a description of the suspect attempting to pass them and the car being driven, keep the bills and call police at 410-548-1776.