SIOUXLAND -- Police in South Sioux City continue to crack down on counterfeiters.
They say they're looking into a fake $20 bill that a 16 year old boy tried to use at a convenience store Tuesday night.
The boy was not arrested, as police are trying to determine if he knew the bill was fake or if he tried to use it accidentally.
This is just the latest in a string of incidents in Siouxland involving counterfeit currency over the past six weeks.
Several police departments are looking into the funny money, trying to track down its source.
Police in North Sioux City are also warning people to be on the watch for counterfeit cash.
In a posting on their Facebook page, North Sioux police say there have also been cases of counterfeit money in North Sioux.
They're asking the public to always take the time to check money they get in transactions, and call police if they have any suspicions about the cash they get.