Robots disarmed three devices found hidden on the bank's property.
"One bomb would be enough but if you have subjects stating more than two, that is highly unusual," said Hopkins County Sheriff Frank Latham.
Nearby Hanson Elementary School was put on lockdown and traffic was diverted from the area for several hours while investigators secured the scene. Investigators are looking for a white male, last seen wearing gray camouflage and a mask.
Copyright 2016 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.