Anti-Trump protesters, attendees clash at 'Deploraball'

Hundreds of protesters demonstrating against Donald Trump clashed with guests leaving an event in honour of the new US president in Washington late Thursday, prompting police to use chemical spray on the crowd.

The protesters, who heckled guests and shouted foul language at people leaving the "Deploraball", also burned protest signs, creating a smoke-filled scene in front of the National Press Building, where the event was held.

Dozens of police, many in riot gear, were on scene, with some trying to help ball-goers, dressed in tuxedos and evening dresses, leave the area as demonstrators chased them down the street.

Although largely peaceful at first, the protest grew more ragged as the night drew on.

Several prominent members of the so-called "alt-right" movement reportedly organized or were to attend the event, held on the eve of Trump's inauguration.

"They don't care about diversity, they don't care about different people, they don't care about homosexuals, they don't care about women, most importantly to me, anyway, as a woman," protester Alex Christopher, who traveled to Washington from West Virginia, told AFP.

Brandon Bourg, a 22-year-old law student attending the "Deploraball" from Louisiana told AFP: "You know -- First Amendment, freedom of speech, freedom to be violent, it's good."

"Violence solves things... but I mean, we're the ones that won in the end," he said.

The name of the event is a play on Hillary Clinton's campaign statement criticizing half of Trump's supporters as a "basket of deplorables."

Trump will be sworn in as the 45th president of the United States Friday, with an estimated 800,000 people expected to gather on the National Mall to watch.

Small demonstrations have already popped up across the city center with protesters declaring Trump illegitimate. A much larger rally is planned for Saturday.