Students at Oberlin College in Ohio are on edge following a recent spate of hate-filled incidents.

The school canceled classes on Monday after a student reported seeing a person wearing a Ku Klux Klan-type hood and robe on campus early Monday morning. The sighting took place near the African Heritage House.

Sunceray Tavler, the student who reported the sighting, told Cleveland's Fox 8: “As I was in the car, I saw someone in what seemed to be KKK paraphernalia walking on a pathway that's like a pathway that leads to south campus. And just like seeing that and having it sink in, like this is something that's real, that actually happens.”

Classes resumed on Tuesday. But more than a dozen messages of hate have been found on campus over the past month. Some were anti-gay, others read, “Whites only.”

“Oberlin has such a reputation for being a very open and accepting place, where people of any walk of life can come and live,” Joshua Blue, a freshman, told CNN. “I mean, that someone was threatening that way of life was kind of scary.”

Oberlin was a center for abolitionists and a stop on the underground railroad, the network of safe houses used by 19th-century black slaves escaping to freedom in the North and Canada.