Police have been unable to locate a woman who entered the Pi Kappa Alpha fraternity house without permission on Thursday and began to masturbate on a couch.

While fraternity members were eating in the dining room, a woman entered the house's living room, took off her clothes and started masturbating, said LSA junior Dan Nye, the president of the Washtenaw Avenue fraternity.

No one saw the woman enter the house or knew how she got in. Nye said she could have entered through the front door, which was left propped open while it was being repaired.

Fraternity members asked the woman to leave the house, but she refused and continued masturbating for about half an hour, Nye said.

When members asked the woman if she was all right, she casually replied that she was fine, he said. The woman was talking on her cell phone at one point, said LSA sophomore Adam Bayard, a member of the fraternity.

She walked out of the front door wearing only a thigh-length black coat after a fraternity member called the police, Nye said. When police arrived minutes later, the woman had already left.

According to a police report, the woman was between 20 and 30 years old, had short brown hair and appeared to be under the influence of drugs.

"Obviously, she was very disturbed," Nye said. "It was not how a normal person would respond to people."

The woman told fraternity members that her name was Melissa and she was a student at Eastern Michigan University, according to the police report.

Fraternity members said they will throw out two couches in the living room because of the incident, Nye said.

Police said the break-in appeared to be an isolated incident.