Just after 9:30 a.m. a man in sunglasses and carrying a silver revolver entered the First American Bank branch at 11821 S. Western Ave. in Chicago.
He announced the robbery and demanded cash from bank employees, according to the FBI. There were no reports of injuries.
The suspect is about 5-foot-ten, and was wearing dark clothing and a dark cap, the FBI said. He left on foot.
In security camera photos he is seen pointing the revolver over the counter of the bank.
Investigators ask anyone with information about today's robbery to call the FBI at 312-421-6700.