SYRACUSE, N.Y. — It was an ordinary cram session, around midnight, when the screed appeared on students’ phones. A racist manifesto, sent to a small clutch of people sitting at a Syracuse University library on Tuesday morning, warned of “the great replacement,” a right-wing conspiracy theory that predicts white genocide at the hands of minority groups.

It was just the latest example of racist activity that has left the private university besieged, with officials confronted by student sit-ins and harsh critiques from faculty members and federal agents crawling the campus.

The incidents, which began less than two weeks ago, have included racist graffiti, swastikas and hate speech hurled at black and Asian students.

On Sunday, the university suspended all social activities at fraternities for the rest of the semester, after a group of students, including members of one fraternity, accosted a female African-American student on Saturday night and used a racial slur.