Thousands of protesters around the country took to the streets Wednesday to condemn the election of Donald Trump as president.

Protesters burned an orange-haired Donald Trump head in effigy, lit bonfires and blocked traffic late Wednesday as anger over the billionaire's election to the presidency spilled onto the streets of major cities.

From New York to Los Angeles, thousands of people marched, rallied and chanted in around 10 cities against the billionaire president-elect a day after his stunning upset win, some carrying signs with slogans such as 'Not our President' and 'Love trumps hate'.

Participants who included both supporters of Democratic nominee Hillary Clinton and independent Vermont Sen. Bernie Sanders, who lost to Clinton in the primary expressed anger at both Republicans and Democrats over the election's outcome.

Most of the rallies were peaceful. The only major violence was reported in Oakland, California, during a protest that began shortly before midnight and lasted into early Wednesday morning.

Some demonstrators set garbage bins on fire, broke windows and sprayed graffiti at five businesses in the downtown area, police said. No arrests were made.

Protesters carrying signs reading 'Dump Trump' gathered outside Trump Tower on Fifth Avenue, where the president elect lives. Police installed barricades outside Trump Tower to keep the demonstrators at bay. The Manhattan protest drew about 1,000 people.

Police said they had arrested 15 people, the New York Times reported.

In Washington, several hundred gathered in front of the White House for a candlelight vigil on a damp, chilly evening, criticising what they called Trump's racism, sexism and xenophobia, and carrying signs reading 'We have a voice!' and 'Education for all!'

One of the organisers, Ben Wikler, Washington director of the liberal advocacy group MoveOn.org, told the crowd that others were coming together in hundreds of communities around the country.

"People are justly frightened," he said. "We are here because in these darkest moments, we are not alone," he added, before leading chants of "We are not alone!"

Protests were also held in Chicago, Philadelphia, Boston, Portland and other cities.

Chicago resident Michael Burke said he believes the president-elect will "divide the country and stir up hatred." He added there was a constitutional duty not to accept that.

Hundreds of University of Texas students spilled out of classrooms to march through downtown Austin. They marched along streets near the Texas Capitol, then briefly blocked a crowded traffic bridge.

In Oakland, California, protesters lit fires in the street and stood around them chanting, news reports said. Some threw bottles and firecrackers at police, KPIX TV reported.

In Los Angeles, demonstrators outside City Hall held aloft a burning, box-shaped likeness of Trump's head, topped with bright orange hair.

Ethan Miller of the workers' rights group Jobs with Justice said organisers held the Washington vigil to show that civil society was resilient.

"It's a hard time for a lot of Americans," he told AFP. "We saw a campaign that was filled with racism and misogyny and whole host of other terrible tactics that ultimately were successful for winning the electoral college."

"But we're not going to let a Donald Trump presidency stop the progress in this country," he added.

Electoral system 'broken'

In New York City, demonstrators gathered in Union Square holding signs saying 'Love Trumps Hate' before marching uptown in the thousands to chant in front of Trump Tower.

"The electoral college is broken," protester Nicholas Forker said of the US indirect voting system. "I think it definitely needs to be reformed... I think it's ridiculous."

In Chicago, several thousand people gathered around Trump Tower, blocking downtown streets and traffic while other staged a counter-protest on the opposite side of the building.

In Boston, thousands of anti-Donald Trump protesters streamed through downtown, chanting "Trump's a racist" and carrying signs that said 'Impeach Trump' and 'Abolish Electoral College'.

The protesters gathered on Boston Common before marching toward the Massachusetts Statehouse, with beefed-up security including extra police officers.

Across the country, high school and college students also staged campus demonstrations and walkouts from classes.

In Oregon, demonstrators blocked traffic in downtown Portland, forcing a delay on two light-rail lines. The crowd there grew to about 300 people, local reports said, including some who sat in the middle of a road to block traffic. Others burned American flags.

In Pennsylvania, hundreds of University of Pittsburgh students marched through the streets, with some in the crowd calling for unity.

The rallies followed protests overnight on Tuesday as voting results were being tallied, when at least one person was seriously injured in Oakland, California, where demonstrators broke store windows and set garbage alight.

A gunman opened fire in downtown Seattle on Wednesday evening following an argument and wounded five people, one man critically, not far from protests against the surprise victory of Republican Donald Trump in the United States presidential election.

The shooting did not appear to be connected to the anti-Trump demonstrations but instead stemmed from a personal argument, said Robert Merner, assistant chief of the Seattle Police Department.

“It appears that some type of argument took place. This individual began to walk away from the crowd, then turned and fired into the crowd,” Merner told reporters.

He said the suspect then fled from the area on foot and remained at large more than an hour later.

The most seriously injured victim, a man, was rushed to nearby Harborview Medical Center, where he was listed in critical condition on Wednesday night.

The other four victims, identified only as one woman and three men, all sustained non-life threatening wounds to their legs, police said.

Police and fire crews were on the scene in less than a minute because they had been in the area to monitor the demonstrations, he said, but did not arrive in time to engage the suspect.