LOS ANGELES (CNS) — Thousands of revelers descended on downtown Los Angeles and other parts of the city Saturday to celebrate the victory of former Vice President Joe Biden over President Donald Trump.

The downtown gathering -- which began as a planned protest against Trump -- turned into a victory celebration after multiple media outlets reported that Biden would win Pennsylvania's 20 electoral votes, putting the Democratic ticket of Biden and California Sen. Kamala Harris over the 270 needed to win the presidency.

A phalanx of riot-clad Los Angeles police officers lined Spring Street outside the LAPD headquarters and the former Los Angeles Times building as throngs of happy demonstrators waving American, Mexican and Armenian flags marched past and began to congregate around the new federal courts building on First Street.

Cars, sprouting American flags and blaring their horns, drove around the demonstrators.

No arrests were made and there were no reports of injuries, LAPD Officer Tony Im said.

The coalition of labor unions and advocacy groups that had planned a protest march against what they called Trump's premature victory declaration said the announcement of a Biden victory only strengthened their resolve to press Trump to accept the results of the voting and concede defeat.

Several marches and rallies downtown culminated at Pershing Square shortly before noon in a "mass march" to Los Angeles City Hall. By noon, thousands of people had gathered downtown.

Organizers said participants were required to remain nonviolent and all attendees must wear a mask and follow local COVID-19 public health orders and social distancing guidelines.

L.A. County health officials urged demonstrators to be as careful as possible, with coronavirus cases still spiking across the county.

"As a reminder, public celebrations where people are close to each other, unable to stand 6ft apart, cheering & shouting, especially without face coverings is high risk for transmission of COVID-19," the department tweeted Saturday.

Other impromptu celebrations were breaking out Saturday as well, with music and dancing filling the streets of Echo Park, and a celebration in Venice as well.

The results are unofficial, and Trump promised legal challenges in numerous states where mail-in votes were still being counted after Tuesday, and where Biden had overtaken his lead.

Meanwhile, supporters of the president held their own rally Saturday in Beverly Hills, as they have for the past several weekends.

Biden issued a statement Saturday morning declaring victory.

"I am honored and humbled by the trust the American people have placed in me and in Vice President-elect Harris. In the face of unprecedented obstacles, a record number of Americans voted. Proving once again, that democracy beats deep in the heart of America," he said.

"With the campaign over, it's time to put the anger and the harsh rhetoric behind us and come together as a nation. It's time for America to unite. And to heal. We are the United States of America. And there's nothing we can't do, if we do it together."

Biden also scheduled an address to the nation for 5 p.m. PST from Wilmington, Delaware, where he was expected to be joined by Harris.

Harris also acknowledged the moment, tweeting: "This election is about so much more than @JoeBiden or me. It's about the soul of America and our willingness to fight for it. We have a lot of work ahead of us. Let's get started."

She tweeted a video moments later showing her on phone call with Biden, saying through laughter, "We did it, we did it, Joe. You're going to be the next president of the United States."

An hour before Biden was declared the winner, Trump issued an all-caps tweet that said, "I WON THIS ELECTION, BY A LOT!"

That followed an earlier tweet from the president that "Tens of thousands of votes were illegally received after 8 P.M. on Tuesday, Election Day, totally and easily changing the results in Pennsylvania and certain other razor thin states. As a separate matter, hundreds of thousands of Votes were illegally not allowed to be OBSERVED..."

As Biden was declaring victory, Trump's lawyer and former New York City Mayor Rudy Giuliani was holding a news conference in Philadelphia claiming that election officials in that city failed to follow proper procedures to inspect mail-in ballots.

Trump himself issued the following statement Saturday, according to NBC News:

"The simple fact is this election is far from over. Joe Biden has not been certified as the winner of any states, let alone any of the highly contested states headed for mandatory recounts, or states where our campaign has valid and legitimate legal challenges that could determine the ultimate victor.

"Beginning Monday, our campaign will start prosecuting our case in court to ensure election laws are fully upheld and the rightful winner is seated."

The coalition members planning Saturday's events said they will "lead a mass action with basic principles that should have long been our standard for all economic and social policy: we care for ourselves, we care for others and everyone counts. It is time ... to stand united, not only to defend but strengthen our democracy by advancing justice and inclusion."

The coalition includes organizations and groups such as Black Lives Matter-LA, the California Faculty Association, CHIRLA, Community Coalition, Democratic Socialists of America-LA, Refuse Fascism, Extinction Rebellion, Ground Game LA and a number of other groups and labor unions.

LAPD Officer Drake Madison told City News Service that officers will take the same action they always do during protests, which is to "hope for the best, but plan for the worst."

"Most importantly, we're there to (let people) express their First Amendment rights, and hopefully L.A. residents will protest peacefully," Madison said.