Sigma Alpha Epsilon, one of America’s largest college fraternities, closed its chapter at the University of Oklahoma late Sunday after a video posted hours earlier appeared to show fraternity members singing a racist chant. The university administration said it was investigating.

The video shows a group of young white people in formal wear riding a bus and singing a chant laden with antiblack slurs and at least one reference to lynching. A grinning young man wearing a tuxedo and standing in the aisle of the bus pumps his fist in the air as he chants, while a young woman seated nearby claps.

The chant vows that African-Americans will “never” be allowed to join the campus chapter. The video was first reported by The Oklahoma Daily, a student newspaper, that said it learned about it from an anonymous tip sent by email on Sunday.

Brad Cohen, the fraternity’s national president, said in a statement that after viewing the video, the organization’s board had decided “with no mental reservation whatsoever that this chapter needed to be closed immediately.”