Updated at 3:19 p.m.: Revised to include comments from bartender, additional information.

Newly released video shows several prominent members of the so-called alt-right movement singing "America the Beautiful" while others give Nazi salutes at a Dallas bar last year.

In a Facebook post Thursday, a bartender said the group was promptly kicked out of the bar.

The footage, obtained by BuzzFeed News as part of a trove of documents related to the inner workings of Breitbart News, shows former Breitbart provocateur Milo Yiannopoulos singing at One Nostalgia Tavern in northeast Dallas.

As the camera pans around, prominent alt-right leader Richard Spencer is among those visible giving Nazi salutes.

The post on the bar's Facebook page referred to Yiannopoulos as a "scumbag" and said that bartender Amiti Perry took the microphone from him and kicked the group out of the bar.

"They do not represent us and should not be associated with our bar in any way," the post says.

Perry told the Dallas Observer that she didn't know who the men were but thought it was "very odd" that they all had similar crew-cuts.

"They started 'America the Beautiful,' and I looked at my co-workers and said 'This is odd,'" Perry told the Observer. "Then all of the sudden, halfway through the song, I see, from behind the stage, about 15 arms go up in the salute."

Perry — who noted that the group didn't tip for their drinks — said she ran up to the stage, took the microphone and started yelling at the group to leave as some of them started chanting "Trump! Trump! Trump!" The men left after other bar employees interceded.

"It was crazy and weird, you know, it felt like The Twilight Zone," Perry said.

The incident occurred in April 2016, several months before Donald Trump appointed Breitbart chairman Steve Bannon to run his presidential campaign. Bannon later served as chief White House strategist before leaving the administration in August and rejoining Breitbart.

Yiannopoulos ran the tech section of Breitbart until February, when he resigned after a video surfaced of him making comments that appeared to defend pedophilia. He apologized for the remarks.

He told Buzzfeed in a statement that he didn't see the Nazi salutes at the bar because of his "severe myopia" — referring to nearsightedness but using a term also commonly applied to a person who is unimaginative or lacks intellectual insight.

Spencer, who grew up in Dallas and attended St. Mark's of Texas prep school, grew in prominence as an alt-right leader during the 2016 elections and gained notoriety when his supporters gave Nazi salutes as he chanted "Hail Trump! Hail our people! Hail victory!" during a conference in Washington, D.C.

In December, he said that America "belong[s] to white people" at a heavily protested speech at Texas A&M University.

The "alt-right" is a radical conservative ideology that mixes white supremacy, populism and a fervent resistance to multiculturalism and globalism. Its followers reject more rights for nonwhites, women, Jews, Muslims, gays, immigrants and other minorities.

Many alt-right adherents supported Trump in the election, though he later said he disavowed them.

In August, however, Trump said there were "very fine people on both sides" of a rally in Charlottesville, Va., where neo-Nazis were among those protesting the removal of a statue of Robert E. Lee. An Ohio man was charged with murder after plowing his car through a crowd of counterdemonstrators, killing 32-year-old Heather Heyer and injuring 20 people.