NORMAN, Okla. - The president of the University of Oklahoma severed the school's ties with a national fraternity on Monday and ordered that its on-campus house be shuttered after several members took part in a racist chant caught on video.

President David Boren said he was sickened and couldn't eat or sleep after learning about the video Sunday afternoon. The video, which was posted online, shows several people on a bus participating in a chant that included a racial slur, referenced lynching and indicated black students would never be admitted to OU's chapter of Sigma Alpha Epsilon.

Boren attended a predawn rally organized by students and lambasted those fraternity members as "disgraceful" and called their behavior "reprehensible." He said the university was looking into a range of punishment, including expulsion.

"This is not who we are," Boren said at a news conference. "I'd be glad if they left. I might even pay the bus fare for them."

National leaders of Sigma Alpha Epsilon said late Sunday that its investigation confirmed members took part in the chant and announced it would close the local chapter. The national group said it was "embarrassed" by the "unacceptable and racist" behavior.

Boren said members have until midnight Tuesday to remove their belongings from the fraternity house. He said the fraternity was "not totally forthcoming," and he was still trying to find out who was on the bus so the school could consider disciplinary actions.

He said the university's legal staff is exploring whether the students who initiated and encouraged the chant may have violated Title VI of the Civil Rights Act, which prohibits racial discrimination.

"We are also going to look at any individual perpetrators, particularly those that we think took a lead in this kind of activity," Boren said.

It's unclear who recorded the video. Boren suggested it was likely taken by another student who didn't agree with what was being chanted.