College students and administrators are struggling to deal with racist incidents on campus despite repeated condemnations.

This week alone, Bucknell University expelled three students for making racist comments during a campus radio broadcast, and Duke University said one of its students placed a noose in a tree on campus. Earlier, spray-painted swastikas and nooses were found at the State University of New York’s Purchase campus, and a former University of Mississippi student was indicted for tying a noose on the statue of the university’s first black student.

National attention turned to the issue earlier this year after a University of Oklahoma fraternity was caught on video singing a racist chant.

University administrators say they are working with students to confront racism, and are punishing perpetrators.