Bernie Sanders left before giving an anticipated speech in Seattle when the event was disrupted by activists claiming to be affiliated with the Black Lives Matter movement, who took over the stage, the Seattle Times reports.

The Saturday event began at 1 p.m. and drew thousands. Sanders was slated to speak at the event, commemorating the anniversary of social security and Medicare, the Washington Post reports.

A brief video taken at the event shows a woman on stage yelling at the crowd, "You guys are full of bullsh*t with your 'black lives matter. Listen." The crowd begins booing, and she says, "My name... You're never gonna hear Bernie speak unless I hear it silent in here now."

A video posted to Twitter shows two young women confronting a man who said they could speak "after Senator Sanders."

According to The Hill, one of the activists identified herself as Marissa Johnson, told the crowd they were racist progressives.

"I was going to tell Bernie how racist this city is — with all of its progressives — but you’ve already done that for me. Thank you," she said. "If you care about Black Lives Matter, as you say you do, you will hold Bernie Sanders specifically accountable for his actions."

She said that after being confronted by activists at Netroots Nation, Sanders has "yet to put out a criminal justice reform package like O’Malley did."

The activists also spoke about local inequalities, including disparities in schools and gentrification. They then asked for a moment of silence to commemorate the one-year anniversary of the death of unarmed black teen Mike Brown at the hands of Ferguson police officer Darren Wilson.

Brown's death had galvanized the Black Lives Matter movement.

Sanders left the event without speaking.

Activists from the Black Lives Matter movement interrupted Sanders at the Netroots Nation event last month and at that time had asked him, "Will you put forward a racial justice agenda that will dismantle, not reform, not make progress, but will begin to dismantle the structural racism in the United States?"

Watch footage of the event here: