It happened around 2:52 p.m. Saturday at the TD Bank branch located on the 500 block of West Germantown Pike.
Police say one suspect presented a demand note to a teller. Soon after, he jumped the bank counter and displayed a handgun.
After obtaining an unknown amount of cash, the suspects fled the area of the bank.
Suspect No. 1 is described as a black man in his late 20s, about 5 feet 9 inches tall and 165 pounds, with teardrop tattoos around his right eye and star tattoos near his left eye. He was seen wearing a white T-shirt, jeans, navy Nike cap and eyeglasses.
Suspect No. 2 is described as a black man in his early to mid-20s, about 5 feet 9 inches tall, with a thin build. He was seen wearing a maroon, hooded sweatshirt, jeans and a tan cap.
The suspects are considered armed and dangerous.
Anyone with information is asked to call the FBI at 215-418-4000 or the Plymouth Township Police Department at 610-279-1901.