FAIRFAX, Va. (WUSA) -- George Mason University police are investigating an alleged sex assault on campus.
Campus officials did not send out an alert to students. They say they don't believe there is a threat to the campus community.
But It's the lack of information about the assault that has some students worried.
Katie Horn is a freshman and was heading to church Sunday morning when she noticed lots of police activity.
She says, "There was a group of them. There were three cop cars sitting at the entrance. Three state troopers talking and two George Mason University police officers."
Crystal French, also a freshman, looked out her window and thought, it was strange seeing so many police officers.
She says, "I was wondering why they were there. I just figured they were checking the meters."
But parking meters were not what police were after but a possible suspect. Campus officials say the freshman was acquainted with her attacker.
Horn says, "I'm shocked, I've never heard anything like that happening at Mason."
George Mason University Police would not go on camera Sunday, but would only say they are investigating an alleged sex assault on campus and that Fairfax County Police are helping them with the case.
Police arrived at Madison Hall, a co-ed dorm, located at Presidents Park on campus around 5 o'clock Sunday morning.
Katie Blacklege is a GMU freshman and says, "It's awful, I hope it's not true. but if there were actually police here, it seems more serious."
Students use key cards to swipe themselves in and get access between halls. But students say that's a false sense of security.
French says, "People let people in all the time. There are so many doors you can go into. There are a lot of young women who walk around at night by themselves, like me, I run at night by myself. Knowing that, that happened, I'll be more cautious about that."
Katie Horn's parents visit their daughter every Sunday and are not surprised to find trouble on college campuses.
Art Horn says, "It disturbs you, but it's the sign of the times. When you put this many people together and on the weekend, things can happen.
Fairfax County Police had no comment on the case Sunday. Campus officials say no one is in custody and the people involved are being questioned. They say they'll provide more information Monday.