Police at the University of California, San Diego, are investigating a second noose found hanging in a campus building in what may be the latest in a series of incidents increasing racial tensions at the university.

School spokesman Jeffrey Gattas said a thin piece of rope fashioned in a crude loop was found last week hanging from a stairwell in Mandeville Hall.

To many African-Americans, nooses are a symbol of historical oppression and lynchings.

Racial tensions have run high at UCSD since February, when students hosted an " Compton Cookout'' themed off-campus party mocking Black History Month. An invitation on Facebook urged female participants to dress as "ghetto chicks'' and said fried chicken, watermelon and malt liquor would be served.

Several weeks later, campus protests were held after another noose was found dangling in the library. A student later admitted placing it, apologized and was suspended.

In March, a KKK-style hood was found draped over a campus statue outside the campus main library.

Blacks make up less than 2 percent of UCSD undergraduates.