STUART, Fla. (CBS12) — Four people are in custody on Tuesday after investigators say they tried passing counterfeit $100 bills at two Publix stores in Martin County.

The Martin County Sheriff’s Office said the suspects first attempted to use the fake currency at a Publix, where cashiers became suspicious of the bills. Authorities say those concerns helped alert investigators to the alleged scheme.

Deputies later located the group at a second Publix store, where all four suspects were taken into custody, MCSO said. Investigators believe the group was attempting to use counterfeit $100 bills at both locations.

No injuries were reported, and authorities have not yet released the identities of the suspects or the specific charges they may face. It was also not immediately clear how much counterfeit currency was recovered or whether additional businesses may have been targeted.

The sheriff’s office says the sheriff will hold a news conference at 2:30 p.m. Authorities also plan to release photos and the seized money later Tuesday afternoon.

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The case comes as authorities on the Treasure Coast continue to warn businesses and shoppers about a rise in counterfeit currency. In recent months, MCSO has investigated multiple incidents involving fake bills used at restaurants, convenience stores, and retail chains, including cases where counterfeit money shared identical serial numbers – a red flag investigators say often points to an organized operation.

Just last fall, sheriff’s officials also cautioned retailers and consumers about fake $20 bills circulating during busy shopping periods, urging employees to closely inspect cash payments and report anything suspicious immediately.