Police say 26 people arrested after peaceful protest turns into riot with property damage.

Thousands of people moved through the streets of downtown Portland on Thursday night to speak out on a wide range of issues, including the election of Donald Trump.

People turned out in droves, about 4,000 gathering first at Pioneer Courthouse Square. It was the third night people have protested in the city since Trump won Tuesday’s general election.

Marchers, mostly peaceful, blocked traffic on downtown streets and bridges. Some marchers clashed with bystanders during the protest. A person smashed the windshield of a woman’s car during an altercation, and graffiti was spray painted on buildings and at least one vehicle during the march.

Late in the evening, what appeared to be a small subgroup of self-described anarchists began to damage cars at a Toyota dealership and ignite fireworks, before moving through the Pearl District and damaging several businesses.

Around 8:30 p.m., Portland police called the action a riot. The police bureau wrote in a social media tweet that authorities arrested 26 people.

Officers in riot gear guided peaceful marchers in the group toward Pioneer Courthouse Square at about 10 p.m. Several people who ignored the orders to disperse were detained by police.

At about 9:45 p.m., several hundred protesters crossed the Broadway Bridge and paused at the corner of Northwest Lovejoy Street and 13th Avenue. Windows at the Bank of America ATM room were broken.

Some in the crowd carried green, white and blue Free Cascadia flags. The crowd included a woman on stilts with a purple peace flag who led a chant of “peaceful protest,” which was taken up by the majority of the group, which headed south toward downtown.

Many businesses throughout downtown and the Pearl District had smashed windows.

‘Professional protesters’

Early in the evening, many people carried signs reading “Not My President,” “Love Trumps Hate” and “Save the Earth.”

Portland activist Greg McKelvey, who has helped manage actions with the group Don’t Shoot PDX, said Thursday that several are groups would be working together under the new name, Portland’s Resistance.

“In order to survive President Trump there needs to be a strong resistance,” he wrote in a press release. “Our group believes that Portland has an opportunity to become a beacon of light for the rest of the nation.”

However, he said the group would also focus on more than Trump, including police brutality, rent control, LGBTQ issues and homeless rights.

McKelvey said he planned to leave the protest as it became more violent throughout the evening.

Peaceful protests took place across the nation in Chicago, New York, Los Angeles and several other cities, with thousands of people marching.

President-elect Trump initially took to Twitter to question the spontaneity of the actions, calling them “professional protesters, incited by the media.”

Tribune reporter Joseph Gallivan, Oregon Public Broadcasting reporters Kristian Foden-Vencil and Bradley W. Parks and KOIN 6 News contributed to this story. Follow OPB coverage at www.opb.org. Follow KOIN 6 News at www.koin.com.