The Sigma Alpha Epsilon fraternity is under fire for another incident of alleged racist behavior after black students at the University of Washington accused local chapter members of calling them “apes” and making obscene gestures, according to The Seattle Times.

The Times said on Thursday that the University of Washington was looking into allegations from members of the school’s Black Student Union that SAE members had harassed them when they marched by the fraternity house during a Black Lives Matter protest on Feb. 25.

Senior neurobiology major Dirir Abhullahi told the newspaper that several white men in front of the SAE house shouted racial slurs at the marchers, including, “You apes, why are you here on our campus.” Several other students said they also heard the slurs.

The allegation comes just days after the University of Oklahoma shuttered SAE’s campus chapter following the release of a video of fraternity members chanting a song that used a racial slur against blacks and said that blacks would never be admitted to the group.

While University of Washington officials said they do not yet know what happened, “the behavior described is completely inconsistent with the university’s values and expectations,” Denzil Suite, UW vice president for Student Life, told the Times.

Michael Hickey, UW SAE chapter president, told the newspaper in a statement that the offensive epithets came from nonmembers of the fraternity who were standing on the sidewalk in front of the fraternity house. He said that the chapter was “concerned and shocked by these allegations, as we pride ourselves in the diversity of our chapter membership and racism is against the moral ethics of our local and national organization.”

The national chapter of SAE did not immediately respond to Al Jazeera’s request for comment about the UW incident, but published on the group’s website was a statement denouncing the Oklahoma incident and supporting the university’s decision to break ties with the local SAE chapter. “There has been no communication from the alumni advisory group to the national headquarters since the chapter closing,” it said. “We support and respect the university administrators’ decision to revoke recognition of the group.”

The statement added: “The fraternity is dedicated to making sure that its members are model citizens and leaders as part of their membership experience but also to understanding how SAE can improve its relationship with men and women of all ethnicities, heritages and nationalities.”

The Black Student Union at UW has asked SAE for a formal apology, and also plans to seek sanctions against the chapter via the school's Interfraternity Council, the Times said.

Members of the former SAE chapter of the University of Oklahoma said Friday that they were planning to file charges against the university and have hired attorney Stephen Jones to represent them, according to KTUL in Tulsa, Oklahoma.

Legal experts have said that the two students from the chapter, who were immediately expelled due to what OU President David Boren called a “leadership role in a racist and exclusionary chant” that had “created a hostile educational environment for others,” may have a case against the school because they were not offered a hearing and have a constitutional right to free speech.

Beyond OU, other SAE chapters have also been punished for alleged racist behavior, including at Washington University in St. Louis, where the SAE chapter was temporarily suspended in 2013 after pledges allegedly sang racist lyrics to a group of black students, according to the Oklahoma Daily.

What’s more, the SAE chapter at Clemson University in South Carolina was indefinitely suspended from campus in December 2014 after members threw a “Clemson Cripmas” party with a gangster theme, modeled after the predominantly-black Los Angeles gang The Crips.

The Washington Post reported that SAE’s national website touted its status as “the only national fraternity founded in the antebellum South.” The fraternity, which was founded in 1856 at the University of Alabama in Tuscaloosa, added that 369 of the group’s 400 members went to fight for the Confederacy when the U.S. Civil War began in 1861, with just 7 members fighting for the Union Army.

The language about the Civil War and the antebellum South appears to have been removed from the website.