Washington CNN  — 

Sen. Bernie Sanders said Sunday that he “never expected in (his) life as an American” to see a Nazi flag waved at a major political rally, several days after a man unfurled one during a speech the Democratic presidential candidate gave at an event in Arizona.

In an interview with CNN’s Jake Tapper on “State of the Union,” Sanders called the incident “unspeakable” and “disgusting.”

“Obviously, it is unspeakable. It is disgusting. It is something – I got to tell you, I never expected in my life, as an American, to see a swastika at a major political rally. It’s horrible,” the Vermont senator said.

On Thursday, a man was kicked out of a Sanders rally after he unfurled a flag with a swastika on it. The man was immediately booed by the crowd. Members of the audience ripped the flag from the individual’s hand, and the individual was quickly removed by security.

The incident, which Sanders said on Sunday he learned about after leaving the stage, sparked an outcry, was widely denounced on social media and prompted calls for security.

“He was behind me. And I was speaking to the crowd and I saw crowds booing and I turned around, I didn’t quite see what it was. I learned about it right after I left the stage,” Sanders said. “The idea that there was a swastika, a symbol of everything that this country stands against – we lost 400,000 people fighting that symbol, fighting Nazism. Six million Jews were killed, other people were killed. The most devastating war in the history of humanity.”

If elected, Sanders would be America’s first Jewish president. Sanders’ extended family from Poland was killed in the Holocaust during World War II. That was a fact referenced in a tweet from former Vice President Joe Biden, also a Democratic presidential candidate, condemning the act as “disgusting and beyond the pale.”

In the moment, in response to the boos, Sanders told the large crowd of his supporters that “whoever it was” that caused the disruption was “a little outnumbered tonight.”

“And more importantly, they’re going to be outnumbered in November,” he added.

The American Jewish Committee tweeted Friday, “Nazi flags are symbols of pure hate and have no place anywhere in America, much less in a rally for a Jewish presidential candidate. We are grateful that those responsible were removed immediately.”

Assault, harassment and vandalism against Jews remain at near-historic levels, according to the Anti-Defamation League, whose most recent audit in 2018 of anti-Semitic incidents showed it was the third-highest year on record since the ADL started tracking in 1979.

The report found a total of 1,879 acts against Jews and Jewish institutions across the country, including the mass shooting at the Tree of Life synagogue in Pittsburgh, believed to be the deadliest attack on the Jewish community in the history of the US.

CNN’s Veronica Stracqualursi and Annie Grayer contributed to this report.