An anonymous student -- identified only as a minority woman -- has admitted to accidentally leaving a noose in a library at the University of California at San Diego last week, an incident that inflamed already tense race relations and set off new protests at the institution, the Los Angeles Times  reported. The student said that the noose was "a stupid mistake" and not intended as a racial comment. The student wrote an apology that ran in the campus newspaper, whose editor said that a "reliable" source had confirmed the letter's authenticity. According to the student, she and some friends had been playing with some rope, making a lasso and a noose, and she took the rope to the library, left it above a desk and forgot it was there. "As a minority student who sympathizes with the students that have been affected by the recent issues on campus, I am distraught to know that I have unintentionally added to their pain," the student wrote.