The suspect was last seen running eastbound on Chestnut Street.
PHILADELPHIA (WPVI) -- Philadelphia police are asking for the public's help in locating a suspect who attempted to sexually assault a young woman early Tuesday morning.
The incident happened around 1:50 a.m. on the 3800 block of Chestnut Street in the city's University City section.
According to sources, the victim attends the University of Pennsylvania. She was taking out the trash at Hamilton Court, an off-campus apartment complex, when she was approached by a man who was armed with a knife.
The suspect was last seen running eastbound on Chestnut Street.
Philadelphia police previously said the victim was sexually assaulted, but in an update on Wednesday morning, police now say the incident was an attempted sexual assault.
Police say the suspect is approximately 20 to 30 years old, six feet tall with short dark hair.
He was last seen wearing a dark-hooded polo shirt, blue denim pants (with stitching along the inseam), and peach sneakers.
Students tell Action News they are remaining vigilant and utilizing safety measures put in place by the university.
"At the beginning of the year they told us to put the Penn emergency people in our saved contacts, that's definitely a resource we've used," said student Lauren Nelegol.
Investigators with the Special Victims Unit are urging anyone with information to call.
"Even if the public saw something that's maybe not important, please let us know. Call it in so we can investigate it," said Philadelphia Police Lt. Tracy Thomas.
Action News has reached out to UPenn but we have not heard back. The university did alert students about the incident via a UPennAlert.
Police say a knife was recovered at the scene.
Anyone who may know this suspect or his whereabouts is asked to contact the Special Victim's Unit at 215-685-3263/64, 215-686-TIPS (8477), or call 911.