University of California San Diego police were investigating a KKK-style hood that was placed on a statue outside the main campus library.
The incident was the third targeting black students at UC San Diego in as many weeks. The other incidents were a "Compton Cookout" party that mocked Black History Month and a noose in a library.
A university statement said the hood was found about 11 p.m. Monday. The object appeared to be a white pillowcase that had been crudely fashioned into a hood with a hand-drawn symbol. A rose had also been inserted into the statue's fingers.
The university said an aggressive investigation was under way, including fingerprint and DNA analysis, and vowed to punish the culprits to the fullest extent of the law.
University officials also said a student admitted she and two other people were responsible for hanging the noose. A statement did not identify the students or their race or include a motive.
In a news conference Friday, Chancellor Marye Anne Fox said the student has been suspended but declined to discuss her motive or other students involved.
"This person admitted her involvement in what we consider to be an abhorrent act," Fox said.
UC and campus authorities did not indicate whether the students would be charged with a hate crime. Under state law, hanging a noose to terrorize is punishable by up to a year in jail.
Students storm office
Hundreds of students rallied for several hours outside the university administration building Friday, where speakers denounced the noose as an example of intolerance on a campus where less than 2 percent of students are black.
The school has been in turmoil over an off-campus "Compton Cookout" party organized by some students that urged people to dress as ghetto stereotypes and promised there would be chicken, watermelon and malt liquor.
Fox condemned the party, and the school began an investigation to determine if any students might face discipline. The school also initiated a campus-wide "Battle Hate" campaign.