Tens of thousands of supporters of United States President Donald Trump on Saturday marched through Washington DC, echoing his unsubstantiated claims of election fraud as he pushes ahead with a flurry of legal moves to overturn President-elect Joe Biden’s victory, Reuters reported.

The police made 20 arrests, including four on gun charges, as Trump supporters and counter-protesters clashed in the streets throughout the evening, according to The New York Times. One person was stabbed, but his condition was unknown till late on Saturday, the newspaper reported.

A week after his Democratic rival clinched the election, Trump has refused to concede to Biden and his administration has rejected any appearance of assisting with the transfer of power. Instead, he continues to claim, without evidence, that there has been a multi-state conspiracy by Democrats to rig the vote tally. Although counting of votes in the United States is still underway, Biden holds a sizeable lead and there has been no indication of improperly counted votes so far that would shift the outcome.

Flag-carrying Trump supporters, however, were out in force on Saturday to complain of alleged electoral fraud.

“Stop the steal!” and “We are the champions!”, they shouted as they marched from Freedom Plaza near the White House to the US Supreme Court building on Capitol Hill. At one point, supporters swarmed Trump’s motorcade as he drove past on his way to his golf course.

The demonstrations were organised under different names, including Million MAGA March – using the acronym for Trump’s Make America Great Again slogan – as well as the March for Trump, and Stop the Steal DC, according to BBC.

Supporters of Trump march in Washington on Saturday. (Credit: Reuters)

Members of the far-right Proud Boys clad in black with some wearing helmets and ballistic vests, were among the marchers, while conspiracy theorist Alex Jones addressed the crowd.

The crowd sang the national anthem, sporadically erupting in cheers for the president. A large number of protesters had travelled across the country – from Los Angeles and Seattle – to show their support for Trump. One group, with the banner “Korean Americans Support 2020 President Trump”, told The Guardian they came in from South Korea for the election and had showed up to support Trump again on Saturday.

By evening, the protest turned violent as skirmishes broke out among Trump supporters and counter-protesters critical of the administration, including members of the loose movement known as antifa.

Near the Supreme Court, some counter-protesters carried black umbrellas and makeshift shields, while others formed a line of bicycles to prevent pro-Trump protesters from approaching their group. They called Trump supporters “Nazis”.

Supporters of Donald Trump clash with counter-protesters in Washington on November 14. (Credit: Jim Urquhart/ Reuters)

Videos on social media showed fistfights breaking out, the police trying to keep the groups apart by forming barricades with their bikes, and protesters near Freedom Plaza, where people lit small fires.