The protesters gathered in Freedom Plaza in the morning as part of the "March for Trump," Organizers expected the crowd to grow to up to 15,000 people, according to a permit from Women for America First, a conservative group, which also organized Saturday's along with last month's "Stop the Steal" rally, USA Today reported.
The Washington Post reported that few demonstrators wore masks and as of midday there were few counterprotesters that include antifa members and local Black activists. The newspaper said hundreds of the Proud Boys -- a group linked to white nationalism -- and six men in the Three Percenters militia were among the crowd.
After the rally at Freedom Plaza, Proud Boys members and counter-protesters got physical with one another at Black Lives Matter Plaza near the White House. Two D.C. police officers were injured trying to separate the two groups, WUSA reported.
WRC-TV reported that four people were taken to a hospital with stab wounds, and the Metropolitan Police Department arrested 23 people.
The protesters marched from Freedom Plaza to the Supreme Court, where former national security advisor Michael Flynn spoke to the crowd. Trump granted Flynn a pardon last month after he pleaded guilty to lying to the FBI during the probe into Russia's interference in the 2016 election.
The march comes one day after the U.S. Supreme Court rejected Texas' effort to overturn election results in four battleground states.
Flynn expressed hope of fighting the election results.
"Don't get bent out of shape," Flynn told the crowd of protesters gathered outside the U.S. Supreme Court. "There are still avenues -- We're fighting with faith and we're fighting with courage."
Trump offered his support to the march participants and Marine One flew over the area en route to the Army-Navy football game at Westpoint, N.Y.
"Wow! Thousands of people forming in Washington D.C. for Stop the Steal," he tweeted Saturday morning. "Didn't know about this, but I'll be seeing them!"
The Electoral College is set to make Biden's 306-232 delegate win official Monday, but Trump and his allies have repeated allegations of voter fraud. U.S. elections and security officials, as well as Attorney General William Barr, have said there's been no evidence of widespread fraud.
Among the rally speakers were former Trump aide Sebastian Gorka as well as South Dakota Gov. Kristi Noem and MyPillow CEO Mike Lindell, both of whom traveled to the capital from COVID-19 hotspots. South Dakota, which has the second-highest rate of COVID-19 infections in the country with 10,136 cases per 100,000, and Minnesota -- Lindell's home -- had on average 85.5 daily cases per 100,000 reported in the past seven days, according to the CDC.