The campus Papa John's Pizza, located at 104 S. 40th St, was robbed at gunpoint early Monday morning, Philadelphia and Penn Police officials said.
A male Papa John's employee, 22 and unaffiliated with the University, reported that two males entered the establishment through the side door at about 12:50 a.m. as the store was preparing to close.
One of the men announced a holdup, brandished a handgun and demanded money from the employee and his manager.
The suspects wore masks and gloves, according to Lt. John Walker of the Philadelphia Police.
They took the complainant's cell phone and removed $1,100 from the register before fleeing the store in an unknown direction.
Walker said it was unknown if the suspects fled on foot or in a car.
No one was injured in the incident, and there are currently no leads in the case.
The Southwest Detectives division of the Philadelphia Police is heading the investigation.
In an unrelated incident on Saturday, a Penn Police officer was assaulted at about 6 p.m. on 40th and Walnut streets, Division of Public Safety officials said.
Penn Police officers responded to a report of a fight in progress at the intersection and encountered a group of men and women arguing.
One male allegedly assaulted an officer by pushing him several times. At the same time, a second male allegedly attempted to grab and remove the officer's handgun.
Both men were arrested by Penn Police.
Eric Calvitti, 21, and John Murta, 23, both of Chalfont, Pa., are facing charges of aggravated assault and other related offenses.
Neither defendant has been linked to other crimes.
DPS officials did not know if any Penn students were involved in the original argument, and no one was injured in the fight.
The incident marks the fifth attack on a police officer or security guard in the Penn patrol area since the beginning of February.
