WASHINGTON (NewsNation Now) — Thousands of supporters of President Donald Trump returned to Washington for weekend rallies to back his efforts to overturn the election.

Sporadic fights broke out between pro-Trump and anti-Trump demonstrators after sundown Saturday. DC Metro Police confirmed that at least 33 people were arrested Saturday afternoon. A 29-year-old man was arrested in connection to reported stabbings near the protests.

The gatherings were intended as a show of force just two days before the Electoral College meets to formally elect Biden as the 46th president. Trump, whose term will end Jan. 20, has not conceded, while continuing to make repeated unfounded claims of widespread fraud that have been rejected by state and federal courts, and Friday by the Supreme Court.

Trump tweeted his apparent surprise Saturday morning at the rallies, publicly known for weeks: “Wow! Thousands of people forming in Washington (D.C.) for Stop the Steal. Didn’t know about this, but I’ll be seeing them! #MAGA”

Trump left the White House around midday for the trip to the Army-Navy football game at the U.S. Military Academy in West Point, New York. As the Marine One helicopter passed over a rally on the National Mall, cheers went up.

Michael Flynn, the former national security adviser recently pardoned by Trump, was speaking from the stage at the time.

“That’s pretty cool. Imagine just being able to jump in a helicopter and just go for a joy ride around Washington,” said Flynn, whose pardon wiped away his conviction for lying to the FBI during the Russia investigation.

At a pro-Trump demonstration in Washington a month ago, Trump thrilled supporters when he passed by in his motorcade en route to his Virginia golf club.

That demonstration, which drew 10,000 to 15,000 people to the capital, ended late in the evening with scattered clashes between Trump’s loyalists and local activists near Black Lives Matter Plaza near the White House.

On Saturday, police took more steps to keep the two sides apart, closing a wide swath of downtown to traffic and sealing off Black Lives Matter Plaza.

But while Saturday’s rallies, including one on Freedom Plaza downtown, were smaller than on Nov. 14, they drew a larger contingent of the Proud Boys, far-right group known for its street violence. Some wore bulletproof vests as they marched through town.

The group saw its profile raised after Trump in September told them to “stand back and stand by.”

After the rallies ended, downtown Washington quickly devolved into crowds of hundreds of Proud Boys and combined forces of Antifa and local Black activists — both sides in an area flooded with police officers. As dusk fell, they stood on opposite sides of a street, with multiple lines of city police and federal Park Police, some in riot gear, keeping them separated.

One Proud Boy yelled out, “You cops can’t be everywhere!” The Proud Boys later dispersed.

Antifa activists also were more organized this time, with their own bicycle corps to form bike walls to match those of the police.

Earlier in the day, a group of about 50 men in the Proud Boys’ black and yellow circled the perimeter of Black Lives Matter Plaza, where about 200 anti-Trump demonstrators were rallying.

They chanted slogans and at one point started singing “Jingle Bells.” They were apparently under orders not to engage with hecklers. One man who was talking back to people was yelled at and told “Don’t interact!”

The assembly on the National Mall, called the “Jericho March,” was described on its website as a “prayer rally” with speakers “praying for the walls of corruption and election fraud to fall down.”

The rally on Freedom Plaza also featured a series of speakers pushing debunked claims of election fraud to a receptive audience.

Among the speakers was Sebastian Gorka, a former Trump adviser, who urged demonstrators not to give up even after Friday’s Supreme Court decision. He said he wanted to send Trump a video and held up his phone, cueing the flag-waving crowd to chant “Stop the Steal.”