The civil unrest and tensions in Portland, Oregon, boiled over again Wednesday night as federal agents sprayed tear gas into a crowd that included Portland Mayor Ted Wheeler.
Wheeler, according to ABC affiliate KATU in Portland, was likely hit with the chemical agent.
"Oh, for sure, he got gassed. I was standing with him, within three feet of him," one protester told KATU. "I think it's giving him a little sampling of those of who have been out here. This is the first time I'd ever seen a mayor, or any public official, be in the depths of what was going on."
Wheeler, who has come under scrutiny from protesters and President Donald Trump alike, was drowned out while trying speaking with demonstrators before tear gas was fired.
"I want to thank the thousands of you who have come out to oppose the Trump administration's occupation of this city," Wheeler told people gathered downtown near the federal courthouse, according to the Associated Press. "The reason this is important is it is not just happening in Portland ... we're on the front line here in Portland."
MORE: Legality of federal agents in Portland scrutinized as protests become more violentAt around 12:30 a.m. local time, the Portland Police Department declared the protest a riot and asked people to leave.
"A riot has been declared outside the Justice Center. Disperse to the north and/or west. Disperse immediately," the department tweeted. "Failure to adhere to this order may subject you to arrest or citation, or riot control agents, including, but not limited to, tear gas and/or impact weapons."
Some of the federal agents in Portland are part of a Department of Homeland Security task force established to respond to the growing protests across the country. The DHS said these forces were there to protect the federal properties from "criminal acts of violence and vandalism."
Thousands are still in the area after the riot was declared and ABC News heard at least seven use-of-force warnings.
Before the riot was declared, Portland police said "multiple flares and other incendiaries" were thrown over the fence surrounding the courthouse, which resulted in fires.
MORE: Trump admin defends use of federal agents in Portland protest crackdownActing Homeland Security Secretary Chad Wolf defended federal agents' presence in Portland earlier this week, saying they are highly trained and are being deployed with proper oversight.
"These officers are not stormtroopers," Wolf said. "They're not the Gestapo, as some have described them. That description is offensive and hyperbolic, and it's dishonest.
ABC News' Kayna Whitworth, Kristofer Rios and Marjorie McAfee contributed to this report.