Thousands of protesters marched Friday night through downtown Portland, outraged at the inauguration of Donald J. Trump as the 45th president of the United States.

Demonstrators shouted slogans and waved signs, maneuvering through several downtown streets and stopping only when they encountered walls of police outfitted in riot gear. The wave of marchers reflected the event's freelance nature – planners didn't seek a permit or share a marching plan with authorities.

The protest largely avoided the intense confrontations – and multiple arrests -- that followed Trump's election in November. But the rainy evening had its flashpoints.

Police used pepper spray at the Burnside Bridge, which was one of four bridges protesters tried to cross, and at least twice more in the evening. Officers used flash-bang grenades to move people from streets and intersections as the crowd spread over six blocks on their uncharted course.

In the fourth hour of the roving march, police fired what appeared to be tear gas to disperse a dwindling crowd at Pioneer Courthouse Square. By that time, a crowd that numbered perhaps 10,000 when the march began shortly after 5 p.m. had shrunk to no more than an estimated 1,000.

In a series of tweets throughout the evening, Portland police said protesters hurled road flares, bottles, eggs and chunks of ice left over from last week's snowstorm. While the demonstration had a chaotic nature, police appeared to have a clear plan that succeeded: keep them from crossing bridges into East Portland.

Police repeatedly closed Willamette River bridges to block protesters' access. Some cars were caught among marchers or in the ensuing traffic jams, but most downtown commuters appeared to leave early or avoid the area.

TriMet said a car blocking tracks on the Steel Bridge, not protesters, interrupted MAX service early in the evening. But transit service in downtown Portland was later suspended during a standoff between police and protesters at the Pioneer Courthouse Square.

Shortly before 8 p.m. about an hour before the march broke up, protesters gathered in front of The Nines hotel near the square. More than a dozen riot police lined up in front of the hotel, appearing to protect a man carrying an American flag. According to reports from witnesses, the man had been involved in a confrontation with protesters. He said he was an Army veteran and was carrying a gun but didn't pull it out.

"We're not against their First Amendment right to protest, we're against how they go about things," said Nick Morris of Gresham. He said he didn't agree with protesters blocking traffic and businesses closing early for fear of the crowd.

At about the same time, a line of advancing officers methodically moved protesters back toward the square. That's where the demonstration originally began with a handful of people burning American flags. A short time later, police announced that they were closing the square and that anyone still there would face arrest.

Gregory McKelvey, one of the protest's main organizers, complained that police roughed up some people unnecessarily. That included a high school student who got pushed to the ground and hit with a rifle, he said. Police spokesman Sgt. Pete Simpson said he couldn't confirm the encounter but that any use of force by police would be reviewed. Police said they arrested six people.

The demonstration was a prelude to Saturday's Women's March on Portland, an event that, according to its Facebook page, is expected to attract 35,000 people along a permitted marching route.

Before and during Friday's march, protesters shared their reasons for participating.

Gabriela Oh, 30, of Corvallis said she was "tremendously disturbed" by Trump's election and his plan to repeal the Affordable Care Act.

"I have health care because of the ACA," Oh said, "and I am tremendously concerned that the Republican administration is not going to replace it with something that will actually make it affordable for me to have health care."

Ricard Patton and his husband, Andy Johnson, flew to Portland from Missoula, Montana. They're concerned gay couples will lose marriage equality rights.

"We rushed our wedding to make sure we got married before Inauguration Day," Patton said.

John Dawson, a 30-year-old small farmer from Damascus, said Trump's presidency will affect him because he's a self-described "queer small farmer who's poor and who gets my health insurance through the ACA."

Connor Flynn, 29, a former Portland resident who now lives in Kalama, Washington, said he attended to hear about of other people's concerns about Trump's presidency.

Flynn said he wanted to "gauge people, look in their eyes, get an impression of people and how they're feeling about all this. And how to act myself and conduct myself as I go forward."

Ian Johnson, an organizer with the Oregon Working Families Party, said he was at the protest because Trump "is diametrically opposed to all of our values from economic equality, gender equality, racial justice and there is no way we can't stand up and be counted here."

The protest featured some chants that gained familiarity in November -- "This is what democracy looks like!" "Stay together stay tight!" "Take off your riot gear, I don't see no riot here!" "Tell me what democracy looks like! This is what democracy looks like!" and one that appeared not to acknowledge the inauguration earlier in the day in Washington, D.C.: "We reject the president elect!"

Downtown businesses prepared for the worst. Nordstrom, Nike and Sephora covered street-level windows with plywood. Some retailers closed earlier than usual.

But the intensity of the rally and march didn't match that of November's, with fewer confrontations between drivers and protesters, a few smatterings of graffiti and no major property destruction. At one point, a dance party broke out in Pioneer Courthouse Square to the strains of "We Are Family" while other demonstrators refused to leave a nearby intersection.

In November, a protest staged downtown on the day after Trump's election raged until 2 a.m. the following day. Vandals smashed cars at a Toyota dealership.

By 9 p.m. Friday, the Inauguration Day protest appeared to be over.

-- Allan Brettman

503-294-5900

@allanbrettman

-- Reporters and photographers Jim Ryan, Samantha Matsumoto, Anna Marum, Elliot Njus, Eder Campuzano, David Greenwald, Noelle Crombie, Everton Bailey Jr., Maxine Bernstein, Molly Harbarger, Dave Killen, Beth Nakamura, Stephanie Yao Long, Mark Graves, Janet Eastman, Grant Butler, Aimee Green and Jamie Hale all contributed to the report.