U.S. Bank, 7525 Madison St., was robbed at 10:51 a.m., according to FBI spokesperson Garrett Croon.
The suspect, described as a 5’9″ white man, 50-60 years old, wearing a green polo shirt, is still at large.
There were no injuries reported. It is not clear what and how much was stolen.
The FBI described the robbery as a non-takeover event, meaning that the robber did not take hostages or attract attention during the robbery.
Croon said he did not know if the suspect was armed.
The Forest Park Police Department was not immediately available for comment.
Croon said FBI agents were still reviewing video surveillance of the robbery and are expected to release images of the robber.