Schools in Charlottesville, Virginia, were closed for the second day in a row on Friday as officials searched for the author of racist threats against the students of Charlottesville High School. An online post threatening “ethnic cleansing” first appeared Wednesday and was later posted on a Reddit thread, the Richmond-Times Dispatch reports. The original post reportedly came from channels frequently used by white-supremacist groups. School Superintendent Rosa Atkins would not confirm the original source of those threats. “I think we all have to keep in mind a threat against one student, no matter what the ethnicity, is a threat against all of our students and a threat against our teachers and our community,” she wrote in an email to parents.