Nationwide protests gripped many cities for days following the presidential election as thousands march against Donald Trump's victory. Trump tweeted to condemn "professional protesters, incited by the media." (Jenny Starrs/The Washington Post)

Demonstrations against the election of Donald Trump as president continued around the country early Friday, taking a decidedly violent turn in Portland, Ore., where police made several arrests after deeming the protests had turned into a “riot” punishable as a “Class C Felony.”

“We reject the president-elect,” many of the demonstrators chanted as they marched through the streets. Elsewhere, thousands of protesters surrounded Trump's buildings in New York and Chicago, clashing with supporters of the president-elect in some areas.

The protests earned recriminations from Trump, who met with President Obama at the White House Thursday morning.

“Just had a very open and successful presidential election. Now professional protesters, incited by the media, are protesting. Very unfair!," Trump said on Twitter.

It was his first comment about the protests and one of few statements he has made since claiming victory over Hillary Clinton early Wednesday morning. In 2012, after Obama was elected to a second term, Trump tweeted: “We can't let this happen. We should march on Washington and stop this travesty. Our nation is totally divided!”

Early Friday morning, Trump took a different tone, tweeting this message: "Love the fact that the small groups of protesters last night have passion for our great country. We will all come together and be proud!"

Condemning Trump's litany of crude comments about women and his attacks on immigrants, demonstrators across the country marched along city streets, blocked intersections, burned effigies and, in some places, gathered outside buildings bearing Trump's name.

“Not my president,” chanted some of the protesters, while others waved signs with the same message.

While many demonstrations late Thursday were peaceful, the vandalism increased in Portland as the night wore on.

Police in Portland, Ore., said that protests against President-elect Donald Trump had turned into "a riot," on Nov. 10, with some smashing windows and lighting fires in the streets. (Jenny Starrs/The Washington Post)

“Due to extensive criminal and dangerous behavior, protest is now considered a riot. Crowd has been advised,” Portland police officials said in a Twitter post late Thursday. The department earlier warned that some drivers were being attacked during the demonstrations and advised protesters to stop the use of “illegal fire devices.”

Police later said that they had arrested 26 people during the night, describing vandalism that occurred in numerous areas and describing those causing the damage as "anarchists."

Teressa Raiford, a community organizer in Portland, said what began as a peaceful Black Lives Matter protest was transformed into something more insidious due to demonstrators not affiliated with the group.

“They’re not coming to show solidarity, they’re coming because they know there’s going to be a big crowd,” Raiford said. “They don’t respect our movement.”

Portland police said on Twitter that some protesters trying to stop the property damage were being threatened by others. “Many in crowd trying to get anarchist groups to stop destroying property, anarchists refusing,” one tweet read. Another police tweet said: “Police advising crowd there are gas and flares being prepared by protestors. Please leave for your own safety.”

They also issued several orders to disperse for “unlawful assembly.”

Mike Bivins, a local freelance journalist, said the protest took a noticeable turn late Thursday as demonstrators passed a Northeast Portland car dealership, where some starting breaking car windows. A dumpster and a newsstand were set on fire.

Bivins said a Black Lives Matter organizer at Pioneer Courthouse Square told demonstrators earlier in the day not to police “anyone else's form of protest.”

“I guess he didn’t think it would rise to this level,” Bevins said.

Khizr Khan, the father of a Muslim U.S. Army soldier killed in Iraq and an outspoken critic of the president-elect, told CNN’s Anderson Cooper that protests are “indicative of how many people have been intimidated, how many people feel that their rights have not been fully guaranteed” because of Trump's campaign rhetoric.

“We appeal to the surrogates of Donald Trump and to him, himself, that he needs to take the first step to make sure that the concerns that are being addressed,” said Khan, who asserted that Trump supporters are “attacking Muslims — Muslim women, snatching their headscarves in New York, in Louisiana, in Los Angeles. Mosques are being attacked by people throwing things. And that needs to stop.”

At least 100 people were arrested Wednesday night during the first wave of national protests, according to police officials, most of them at one in New York. While most of the demonstrations remained peaceful, police in Oakland, Calif., said a rally there turned violent when some in the massive crowd injured three police officers by throwing rocks and fireworks at them.

The unrest underscored the fractures in a country that awoke Wednesday to learn that Trump had pulled off an unexpected victory over Hillary Clinton, his Democratic opponent, and more were planned for the weekend.

Demonstrations started early Wednesday in the biggest U.S. cities — New York, Los Angeles and Chicago — and flared in places from Portland and Seattle to Philadelphia and Richmond, along with cities in red states such as Atlanta, Dallas, Omaha and Kansas City, Mo. But they continued Thursday evening, spreading to Baltimore where police said about 600 “anti-trump” protesters marched to the downtown area and blocked streets. Two protesters, they said, were held but not charged.

Most of the major demonstrations took place in urban centers in blue states Clinton won Tuesday, highlighting the demographic divide that shaped the election results.

Clinton's apparent narrow victory in the popular vote, coupled with her loss in the electoral tally, spurred demonstrators in New York to chant, “She got more votes!” as thousands massed in front of Trump Tower in Midtown Manhattan Wednesday night. The crowd stretched several blocks down Fifth Avenue.

Before that, protesters had marched from Union Square to Trump's building, chanting, “Donald Trump, go away! Sexist, racist, anti-gay!”

At one point, demonstrators lit an American flag on fire. Later, amid a cacophony of loud chants, a glowing “Love Trumps Hate” banner was held aloft under the Trump Tower sign. The singer Cher mingled in the crowd, doling out hugs.

Police in New York said about 65 people were arrested during the first night of protests, mostly for disorderly conduct or resisting arrest.

People in Trump's circle said they were monitoring the unrest and had expected such activity after the election:

On Thursday, former New York mayor Rudy Giuliani (R) called the people protesting “a bunch of spoiled crybabies.”

“We're bringing up a generation of spoiled crybabies,” Giuliani, a Trump adviser who has been touted as a possible attorney general, said in an interview on Fox News. Apparently referencing protests happening around college campuses, Giuliani said: “Most of the kids aren't crying. Most of the kids are going to class.”

At one point Wednesday night, a protester in Los Angeles was interviewed on CNN and spoke about how “there will be casualties on both sides,” language that was condemned by Kellyanne Conway, Donald Trump's campaign manager.

In Florida, Trump supporters spilled out of an Irish bar Thursday to confront the hundreds of protesters making their way through the brick-paved district of Ybor City, the historic epicenter of the Cuban community in Tampa. Some of the Trump supporters, still holding their beers, stood within inches of the protesters, shouting “USA, USA.” Other hurled vulgarities at the crowd.

Local police swarmed the area to separate the groups.

Nearby, a retired Marine Corps corporal, Kyle Mullinax, stood at attention as protesters walked by. The protesters are “stupid,” he said.

In Oakland, police said the crowd of demonstrators eventually grew to about 7,000 people Wednesday and began to splinter into smaller groups, some of which vandalized buildings.

As things became more heated, police said, they used devices releasing tear gas several times. In addition to the three police officers who were injured, three police cars from nearby Pleasanton, Calif. — one of many cities that sent officers to help respond — were damaged, officials said.

Authorities reported 16 cases of vandalism, including graffiti and looting, and said there were “numerous trash fires in the streets." (About 40 fires were extinguished by police and fire officials.) Police said they arrested 30 people and issued an additional 11 citations for vandalism, unlawful assembly and assault on an officer.

In Los Angeles, thousands of protesters filled the streets, including some who burned a giant papier-mache Trump head in front of City Hall and others who spray-painted profanity on the Los Angeles Times building and on vehicles used by news organizations.

Hundreds of other protesters blocked two highways in the area, backing up traffic for miles.

In Chicago, police said about 1,800 people has demonstrated outside of Trump Tower Wednesday. On Thursday, the protests started small, but grew to several hundred people, who marched through downtown streets, stopping traffic for more than two hours.

Jessica Orman, 24, from Chicago, said she is dismayed by the people who voted for Trump and feels that her future is on the line. “I see people differently now. I don't smile at people on the street anymore. Because you never know,” she said.

“I'm so jaded, but we have to fight. We have to protest. I can vote because people protested. I can be on the pill because people protested. Gay people have rights because people protested,” she said.

Orman currently earns about the minimum wage and said she had hoped that if elected Hillary Clinton would raise the minimum wage. Now, she said, her financial prospects could get worse.  “The economy could go belly up.”

MoveOn.org, a liberal group, had called on people to gather in cities nationwide. Ben Wikler, MoveOn's Washington director, said that people had registered to organize events in 275 cities and communities across the country, noting that many were candlelight vigils and group discussions rather than the sprawling marches seen in New York and Chicago.

“A lot of people reacted to the election results with a kind of plodding feeling, like they wanted to curl up under their desks or hide under their sheets,” Wikler said Thursday. “Just knowing that you're not alone in this country is a powerful salve. And knowing there are people that want to continue to fight for a more perfect union is a source of strength at a moment that can feel very scary.”

Tensions ran particularly high on college campuses. At American University in Washington, students burned American flags, and some shouted, “F--- white America!”

In Austin, students at the University of Texas led a march for hours through the city Wednesday afternoon. As hundreds of protesters wove into traffic, bus drivers high-fived the students. Some in their vehicles got out and hugged them, tears streaming down their faces.

“Seeing this is everything,” said Jennifer Rowsey, 47, as the march passed by a coffee shop next to Austin City Hall, where she is the human resource manager. “I felt so isolated,” she said. “I don't feel so alone now.”

Austin City Council member Greg Casar, the son of Mexican immigrants and a community organizer, joined the protesters when they passed him while he was giving an interview to local media.

“A lot of people are calling for healing,” he said. “I think we should reject that.”

He said that now is the time to support protesters, strikers and those engaged in other forms of civil disobedience. Casar said that if Trump comes to Austin, he will refuse to shake his hand. “If I have to go to jail” for protesting, he said, “I'll go to jail.”

Many protesters who turned out said they were fearful that Trump would follow through with his pledge to deport undocumented immigrants.

“I just felt waking up today that I was waking up to a whole new world, to a nightmare for my parents and people I care about and love,” said Tony, a 23-year-old line cook who declined to give his last name as he marched in Chicago, carrying his 6-year-old daughter on his shoulders.

“There's so much heartache,” he said. “It's a bad time to be a Muslim or an illegal citizen in this country.”

In Santa Ana., Calif., Lucy Dominguez, 37, and her husband, Oliver Lopez, 33, had their arms around one another and held a sign reading, “Peace.”

“I came to stand up with the people. To stand up with my people, the Latino community,” she said. “I chose the peace sign because we need peace in this moment.”

During his victory speech early Wednesday, Trump spoke about reconciliation following the bitter campaign, saying that it was “time for America to bind the wounds of division.”

Later Wednesday, this tone was echoed by Clinton and President Obama, who said they were also disappointed after an Election Day that ended with Republicans in control of both the legislative and executive branches of government.

Clinton said the campaign showed that “our nation is more deeply divided that we thought,” but she told her supporters: “We owe him an open mind and the chance to lead.”

But the anger and grief that continued Thursday evening suggested that many fear what Trump's election means going forward.

In Philadelphia, an estimated 1,000 protesters filled the streets chanting slogans such as “We reject the president-elect,” and “hands too small, can’t build a wall.” Police on bicycles moved with the throngs, who remained peaceful as they choked the streets of Center City.

“I feel very dark about the future,” said Janette Chien, 27, of Philadelphia, who voted for Hillary Clinton.

Chien, a first-generation immigrant whose parents were born in China, said Trump’s hostility toward immigrants troubled her. Since Tuesday’s election, Chien said watching her like-minded friends meltdown on Facebook has been grueling.

“It’s just been horrible and exhausting,” said Chien, who works in afterschool programs with children. “We need to fight. If we don’t do anything, it’s just going to continue this way.”

 Leah Sottile reported from Portland; Kari Lydersen reported from Chicago; Nick Romeo in Berkeley, Calif.; Eva Ruth Moravec in Austin; Katie Zezima in Santa Ana, Calif.; Les Neuhaus from Tampa; Bobby Allyn in Philadelphia; Philip Bump, Ryan Carey-Mahoney, Kayla Epstein, Renae Merle and Anne Gearan in New York; and Fenit Nirappil and Juliet Eilperin in Washington contributed to this report, which has been updated since it was published. 

Further reading:

“Something is happening,” Trump said. He was right.

Trump meets with Obama at the White House as whirlwind transition starts