RELATED SLIDESHOW: Pictures of the suspect
In both robberies, the FBI said the man entered the branches and presented threatening demand notes to tellers. After receiving undisclosed amounts of cash in each robbery, the man fled on foot in an unknown direction.
The suspect is described as a black man in his mid to late 40's, 6'1" to 6'2" tall, medium build, with a salt-and-pepper trimmed beard, wearing a white baseball cap, a dark-colored or brown waist-length jacket, tan pants and brown boots.
In Monday's robbery, he was also carrying a black backpack over his shoulder.
He is considered armed and dangerous, and anyone with information is asked to call the FBI at 215-418-4000 or the Philadelphia Police Department.
There may be a reward for information leading to the identification and apprehension.
You can get the latest crime statistics from the Philadelphia Police by CLICKING HERE for the force's crime data mapping site.