Around 10:45 p.m., Joliet police responded to the Heartland Bank and Trust located at 5650 Caton Farm Road for a report of an armed robbery.
Police say a man had entered the bank announcing a robbery, and implied he was armed with a knife.
The man stole an undetermined amount of cash and fled the scene, police said.
The suspect was described as a white male, wearing a dark hooded sweatshirt with a red logo, dark pants, and dark shoes. He also wore a medical facemask, sunglasses and gloves.
Police say there is no threat to the public.
The incident is under investigation by the FBI.