It happened around 11:10 a.m. at 4th and Tabor as the car was making a delivery to a PNC Bank branch there.
The FBI says the truck's driver was heading toward the entrance of the bank when he was approached by a man with an assault rifle.
That man took the delivery from the driver and fled the area in a brown or bronze older model sedan with a "square" back, driven by a different unidentified male. The car was last seen heading westbound on Tabor Street and then southbound on 5th Street.
The armed subject is described as a black male, with a light complexion, mid 20's to early 30's, 5'9" tall, thin build, with a long beard, wearing a hat and a brown leather jacket with a cream-colored or white sheepskin lining.
These subjects are considered armed and dangerous, and anyone with information is asked to call the FBI at 215-418-4000 or the Philadelphia Police Department.
Garda has offered a $25,000 reward for information leading to the arrest and conviction of the subject or subjects responsible for this robbery and the recovery of the money.