The robbery happened at 12:23 p.m. Friday at the Wells Fargo Bank branch located at 340-350 South 2nd Street.
According to police, the suspect entered the bank, handed a teller a demand note, and made a verbal bomb threat. During the course of the robbery he also allegedly assaulted and robbed an elderly female customer.
After obtaining an undisclosed amount of cash from the teller, the man fled the scene. He was last seen heading north on 2nd Street.
The female assault victim suffered minor injuries to her lip and knee, but declined medical attention, police say.
The suspect is described as a white male in his mid to late 30s, approximately 5'7"-5'8" tall, thin build, with a brown beard and mustache. He wore a dark-colored zip-front hooded jacket, blue jeans, a burgundy baseball cap with unknown logo, and light-colored gloves.
Police say the suspect should be considered armed and dangerous.
Anyone with information is urged to call the FBI at 215-418-4000 or the Philadelphia Police Department. There may be a reward for information leading to this subject's capture and tipsters can remain anonymous.