The crime occurred around 12:05 p.m. Saturday, Nov. 8, at a U.S. in the 100 block of Smith Road in St. Charles, Illinois, FBI officials said.
An adult male suspect armed with a handgun entered the bank and demanded money, officials said. He was wearing a camouflage hoodie, a dark medical face mask, dark sunglasses a navy blue Chicago Bears hat and a dark cross-body bag.
The suspect fled on foot and is still at large, the FBI said.
Anyone with information can contact the FBI at 312-421-6700 and tips.fbi.gov.