The University of Oklahoma on Monday ordered a major fraternity off its campus over a YouTube video that shows some of its members singing a racist chant.
The video came to light over the weekend, just as Americans were marking the 50th anniversary of the Selma, Alabama civil rights marches.
The chant uses the racially charged N-word and refers to lynching in affirming that blacks shall never be members of Sigma Alpha Epsilon.
The fraternity on Sunday suspended its University of Oklahoma chapter, but campus officials went further, ordering its members to be off campus by midnight (0400 GMT Tuesday), KOCO television in Oklahoma City reported.
It also opened an investigation to confirm whether any of the 30,000 students who attend the University of Oklahoma participated in the video.
"If OU students are involved, this behavior will not be tolerated and will be addressed very quickly," university president David Boren said in a statement.
"This behavior is contrary to all of our values."
Sigma Alpha Epsilon's national headquarters apologized for what it called "the unacceptable and racist behavior of the individuals in the video."
"This type of racist behavior will not be tolerated and is not consistent with the values and morals of our fraternity," it said in a statement.
The video went viral on social media after it was posted on YouTube on Sunday by Unheard Movement, an African-American student group at the university.
Nine seconds long, it was apparently shot in a bus, with young men in black tuxedos punching the air and a blond woman hoisting a glass of wine.
It's unknown when the video was taken.
KOCO reported that some Sigma Alpha Epsilon members left the fraternity house overnight Sunday under police protection. On the side of the building, graffiti saying "Tear it down" was seen.
With 15,000 members, Sigma Alpha Epsilon is one of the biggest fraternity networks in the United States.