PORTLAND, Ore. >> A federal judge specifically blocked U.S. agents from arresting or using physical force against journalists and legal observers at protests in Oregon’s largest city where President Donald Trump is testing the limits of federal power.

Federal agents appeared to deploy tear gas early today to force thousands of demonstrators from crowding around the federal courthouse.

Protesters had projected lasers on the building and attempted to take down a security fence that had been reinforced to keep demonstrators at a distance. The protesters moved away as clouds of gas rose from the area and flash grenades could be heard.

U.S. Judge Michael Simon made his ruling late Thursday, a day after Portland’s mayor was tear-gassed by federal agents while making an appearance outside a federal courthouse during raucous demonstrations. Protesters have been kept up in the city for nearly two months since George Floyd was killed in Minneapolis.

Simon had previously ruled that journalists and legal observers are exempt from police orders requiring protesters to disperse once an unlawful assembly has been declared. Federal lawyers intervened, saying journalists should have to leave when ordered.

“This order is a victory for the rule of law,” Jann Carson, ACLU of Oregon’s interim executive director, said in a statement.

The judge said objections by law enforcement were outweighed by First Amendment concerns.

“None of the government’s proffered interests outweigh the public’s interest in accurate and timely information about how law enforcement is treating” protesters, he wrote.

Simon’s order is in effect for 14 days. Journalists and observers must wear clear identification, he said. A freelance photographer covering the protests for The Associated Press submitted an affidavit that he was beaten with batons and hit with chemical irritants and rubber bullets this week.

The ACLU lawsuit is one of several filed in response to law enforcement actions during the protests. The state of Oregon is seeking an order limiting federal agents’ arrest powers during the demonstrations.

On Wednesday, Mayor Ted Wheeler and hundreds of others were objecting to the presence of federal police sent by Trump, who labeled the demonstrators as “agitators & anarchists” after Wheeler was gassed.

Wheeler, a Democrat, appeared slightly dazed and coughed and said it was the first time he’d been tear-gassed.

He put on a pair of goggles someone handed him and drank water but did not leave his spot at the front of the raging demonstration — with protesters lighting a large fire between protective fencing and the Mark O. Hatfield Federal Courthouse amid the pop-pop-pop sounds of the federal agents deploying tear gas and stun grenades into the crowd.

It wasn’t immediately clear if the agents knew that Wheeler, a 57-year-old sixth-generation Oregonian and longtime politician, was in the crowd when they used the tear gas.

Wheeler has opposed the federal agents’ presence but has also faced harsh criticism from the protesters, who yelled and swore at him.

Earlier in the night, Wheeler was mostly jeered by protesters as he tried to rally the demonstrators who have clashed nightly with federal agents. But they briefly applauded when he shouted “Black Lives Matter” and pumped his fist in the air.

Trump in his tweet attempted to ridicule Wheeler, calling him the “Radical Left Mayor of Portland, who last night was booed & shouted out of existence by the agitators & anarchists.”

The Justice Department’s inspector general said Thursday it will review the conduct of federal agents who responded to unrest in Portland and in Washington, D.C., after concerns emerged from members of Congress and the public.

City council members accused Wheeler of not reining in police who used tear gas multiple times on protesters before federal agents arrived. And city business leaders have condemned the mayor for not bringing the situation under control before the agents showed up.

Department of Homeland Security acting Secretary Chad Wolf denied that federal agents were inflaming the situation. He told “CBS This Morning” that Wheeler legitimized criminality by going to the front of the crowd of demonstrators where the fires were lit and where people were trying to pull down a security fence.

Wheeler did not participate in lighting any of the fires or attempting to tear down the fence and was surrounded by his security team when he was gassed.

Police said the crowd threw Molotov cocktails, lit fires in a park and in trash cans and released hundreds of gallons of water from fire hydrants.

Wheeler’s appearance in the protest zone came hours after state attorneys for Oregon urged another judge to issue a restraining order against the federal agents. Oregon Attorney General Ellen Rosenblum’s lawsuit accuses federal agents of arresting protesters without probable cause, whisking them away in unmarked cars and using excessive force. Federal authorities have disputed those allegations.

The hearing in U.S. District Judge Michael Mosman’s court focused on the actions of the more than 100 federal agents responding to protests outside the Portland courthouse.

The state’s motion asks Mosman to command agents from the Department of Homeland Security, Customs and Border Protection, Federal Protective Service and U.S. Marshals Service to immediately stop detaining protesters without probable cause, to identify themselves and their agency before arresting anyone, and to explain why an arrest is taking place.