The woman told police that it happened around 2 a.m. Thursday -- just hours after the Duke/UNC basketball game on campus -- in the area behind Ackland Art Museum. The spot is also close to the popular Top of the Hill restaurant on Franklin Street.
Police say the woman was in the alley when she was confronted by two men. All police say the woman has been able to tell them, is that the alleged assault happened near a dumpster, behind the art museum. After the attack, she went to the Cosmic Cantina where someone called for help.
"This thing is still unfolding," said Chapel Hill Police Lt. Kevin Gunter. "We don't know if the two suspects are likely to strike again. We don't know."
Because of those unknowns, the UNC Police Department said they did not issue an official alert to students warning them of the attack. School officials said there was not enough information to reflect a threat to the school.
The school usually issues notices about crime and emergencies through the Carolina Alert System. University guidelines call for alerts to be sent out for conditions that pose a continuing danger to the campus community.
After finding out about the alleged incident, many students were concerned and wished the school would have warned them.
"Even though it didn't happen to a student, something like that should be told to the students," UNC student Leota Amsterdam said.
Chapel Hill police are urging anyone who might have seen anything unusual in the area Thursday morning to contact them.