Watch: Portland police charge Antifa and fire smoke bombs after claiming they 'threw rocks and bottles'

Police in Portland, Oregon have charged at anti-fascist protestors and fired flash-bangs and smoke bombs during a tense standoff at a "Free Speech" rally.

The police claimed they were acting defensively.

"Police have observed protestors throwing projectiles, including rocks and bottles," the police are heard saying in video from the scene.

Washington state Republican Senate candidate Joey Gibson, who leads a pro-trump extremist group from the Portland suburb of Vancouver, Washington, is leading a march of rightwing extremists.

Antifa and other leftists organizations have mobilize to confront the group.

Earlier in the afternoon, Gibson crossed the line into the leftist side of the protest and was brought out by Portland police.

A Nazi flag has also been burned.

Update: The event has officially been labeled a "civil disturbance" by Portland police.

Check back for updates.