Editor's note: Video is from Aug. 17, following the clashing protests

PORTLAND, Ore. — A Multnomah County grand jury filed a four-count indictment against a man arrested during the opposing protests in downtown Portland on August 17.

The indictment charges Alexander Dial, 37, with one count of felony riot, one count of second-degree assault, one count of second-degree unlawful use of an electrical stun gun, tear gas or mace, and one count of fourth-degree assault.

The indictment states that Dial "intentionally and knowingly" participated with five or more people to engage in "tumultuous and violent conduct" and that he "used a dangerous weapon to cause physical injury to another person." It also accuses him of "recklessly [discharging] an electrical stun gun."

MORE COVERAGE OF AUGUST 17 PROTESTS

On August 30, a Multnomah County grand jury indicted Dial and four other men — Zachary Lange, 21; Richard Klimek, 51; Antonio Zamora, 33; and Evan Duke, 48 — on one count of felony riot each.

Lange, Klimek, Zamora and Duke face additional charges.

In a probable cause affidavit, prosecutors said Zamora was one of many "affiliates of Antifa," who surrounded two buses filled with members of the far-right groups Proud Boys and Patriot Prayer as they tried to leave the city in heavy traffic.

Bystander videos of the attack on the buses went viral in the days after the Aug 17 demonstrations.

One video shows left-wing demonstrators — loosely organized and self-described anti-fascists, or "Antifa" — rushing the bus when someone opens the door and exchanging blows with those inside.

Police have arrested 15 people on charges related to the protests on August 17 and continue to investigate.