Kim Van Horn finds herself glancing around as she walks through the Georgetown University campus at night. A student-run escort service is running full for the first time. And with frightening rumors spreading quickly, dozens of students attended a security meeting Monday night.

Georgetown's picturesque campus is rife with stories of rapes and assaults on students, and Dean of Students John DeGioia is at a loss.

"I really can't explain why it's happening, but it is," he said yesterday.

"It" is a series of persistent, detailed rumors of several rapes on or near campus in recent weeks. Virtually everyone on campus is familiar with details, down to exact locations and times of the incidents. But despite efforts by DeGioia, campus police and student activists, no one has come forward to file an official report.

So university administrators, police and student newspapers are caught in a bind. Do they assume the rumors have some validity and so report them as news and step up campus security? Or do they conclude that the stories must be unfounded since no one has confirmed them?

"There has not been any reported rape on campus since 1983," said Sgt. Charles Christian, chief investigator for the Georgetown University Protective Service, a uniformed force of 70 commissioned, unarmed officers.

"I'm of the opinion that these incidents didn't really happen. There's a new women's group on campus that's stirring things up. Now it is possible that it happened, but if it's happened and we don't know about it, it didn't happen as far as we're concerned."

"He shouldn't be saying that," said Alexia Quadrani, a junior from New York and member of the student government's security committee. "People are really frightened. That's the wrong attitude for the university to be taking."

Christian appeared on a campus radio program earlier this week and asked anyone with direct information about attacks to come forward. DeGioia said he has asked dozens of students in the past week if they know anyone with direct knowledge of incidents.

"It's always somebody who told somebody else," he said. "We can't even get to a person who knows the victim. This is not that big a place. I can't imagine that there would not be more details if it were real."

It is real enough to many of Georgetown's 5,600 undergraduates.

"There is a kind of general hysteria," said Liz Moyer, news editor of The Hoya, a student newspaper. "I won't even walk out of my house alone now."

"Everyone is talking about it," said Soraya Chemaly, a senior who is editor of a new campus women's journal. "No one wants to cause panic, but it's better that people be informed and frightened than to just not know anything and not take precautions."

No incidents have been reported to either campus or D.C. police, university officials said. One rape a few blocks off campus was reported to D.C. police last month; the victim was not a student.

The rumors tell of five rapes, including three outside the campus gates and two in a well-lighted, well-trafficked area of the main campus. Students who do not know one another related remarkably similar accounts of the attacks, including locations, time of day and number of people involved.

DeGioia discounted a common student opinion that rape victims are less likely to report attacks because they lack confidence in the campus police.

Last week, the student service fraternity, Alpha Phi Omega, expanded its late-night escort service from the library to dormitories. The service, which had provided walking escorts, now has the use of a university van to drive students home. The service gained instant popularity and runs packed every hour, students said.

A steady stream of students stopped by a Security Awareness Week table set up on the green outside the library Tuesday. They picked up sheets of safety tips for women and wrote suggestions for increased security.

"Hire competent officers," one person wrote. "More light," said another.

Female students said the lack of official confirmation of any incidents involving students has not relieved their fear.

"It's hard to ask someone to come forward and tell the world she's been raped," said Quadrani.