Seoul(CNN) Thousands took to the streets of Seoul to celebrate the dawning of a new political reality in South Korea.
President Park Geun-hye is due to leave office after a Constitutional Court on Friday upheld a vote by lawmakers to impeach her.
With Park out, South Koreans' attention is now turning to what leadership the next election will usher in, and how the new leadership will handle relationships with the US and North Korea.
Police presence in Seoul was heavy Saturday, after violent protests following the court's ruling which resulted in the deaths of three demonstrators.
Pro-Park groups staged an angry demonstration outside Seoul City Hall early Saturday, singing the national anthem and waving Korean and American flags.
But as the sun went down the mood of the city was jubilant, as thousands flocked to a giant celebratory rally on the historic Gwanghwamun Square.
According to the Yonhap news agency, more than 70% of Koreans support Park's impeachment.
Protests amid South Korean President's removal from office
South Koreans celebrate in Seoul after the Constitutional Court
upheld a parliamentary vote to impeach President Park Geun-hye on Friday, March 10. Demonstrators both for and against Park took to the streets after the verdict.
People celebrate after the Constitutional Court's verdict.
Demonstrators wearing illuminated costumes take part in a rally demanding Park's arrest. Now stripped of her immunity, Park is vulnerable to prosecution in the scandal that triggered her removal. Lawmakers and judges agreed that she abused her authority in helping a friend raise donations from companies.
A supporter holds a portrait of Park during a rally opposing her impeachment.
People opposing Park's impeachment cry during a rally near the Constitutional Court.
Police block Park supporters as they march toward the Constitutional Court in opposition of her impeachment.
A supporter of the ousted president lies in a pool of blood as protesters push to pass a police barricade preventing them from reaching the Constitutional Court. According to police, two people died in the protests. A statement from acting President Hwang Kyo-ahn said several people also were injured.
Anti-government activists march toward the presidential palace, known as the Blue House. Park will not leave the Blue House immediately, a spokesman told CNN.
Park supporters clash with police after the country's Constitutional Court announced it would uphold her impeachment.
An effigy of Park is paraded through the streets of Seoul.
Park supporters shout slogans and wave South Korean flags during a rally to oppose her impeachment.
An anti-government activist wears a Park mask.
A Park supporter shouts slogans in front of a police line.
Park supporters clash with police.
Protesters view cutouts of Park and Hwang during a march toward the Blue House.
Park supporters are blocked by police during their march toward the Constitutional Court.
South Koreans celebrate at a restaurant after hearing the court's unanimous verdict.
An injured Park supporter lies on a stretcher surrounded by police.
Seoul music
On stage at Gwanghwamun Square, in front of Seoul's Imperial Palace, rock bands played loud music and there was a festival-like atmosphere.
Unlike an earlier pro-Park rally, attendees at the square represented a cross section of Seoul society, as families with children, students, office workers and trade unionists celebrated together.
"We finally have our weekend back," a presenter shouted from stage. Many of those in the crowd have been turning out every Saturday throughout the bitterly cold winter to call for Park's ouster.
One band played a cover of Queen's "We Are The Champions."
"Today feels like a festival," Mun Ha-neul, 17, said. "Everyone is feeling happy."
South Korea's eleventh President has been impeached, @willripleycnn
University student Kim Ga-yun, 26, agreed. "We've been (protesting) for more than 90 days," she said. "At least today, we should be allowed to have a celebration."
Housewife Lee Dong-sun, 36, who joined many of the protests against Park, had brought her two young sons to the square.
"Before, when there were other protests, I would just sit at home, even when I agreed," she said. "But after I had children, I felt I could no longer ride on the backs of others ... to bring them the future I desire."
Some protesters were wary of celebrating too much. Artist An Hyun-jung, 30, who has been staging performances criticizing Park on Gwanghwamun Square said there was still much to do.
"It doesn't feel like this is the end, I think we will be heading to the next fight," she said.
Faces of Seoul protests
Thousands of South Koreans took to the streets of Seoul Saturday after President Park Geun-hye was officially impeached. While polls suggest most of the country -- as many as 80% -- supports the move, a small minority of demonstrators said they wanted to "impeach the impeachment."
"Young people don't understand," said Song Bok-sung, 80, who was protesting Park's impeachment. "We remember the (Korean War) and how bad it can get."
"There was no reason for this impeachment," said Jason Choi, 36. He added that he was worried the next South Korean government would be soft on North Korea and may reverse the decision to deploy a US missile defense system in the country.
The Park decision shows that "maybe this is a time for the older people to listen to the younger people," said Kim Dae-rim, 30, who had been protesting for weeks for the now former President's impeachment.
"Today feels like a festival, everyone is happy," said Mun Ha-neul (left) and Park Hyun-jin (right), both 17, who were celebrating Park's ouster.
Jang Song-hoi, 38, was gathering signatures to start a new political party representing the youth of South Korea. "We want the youth to be able to make the world they want," he said.
Lee Dong-sun, 36, brought her children to the demonstration celebrating Park's impeachment. "Before, when there were other protests, I would just sit at home, even when I agreed," she said. "But after I had children, I felt I could no longer ride on the backs of others ... to bring them the future I desire."
"Today is just the beginning," said Kim Ga-hyun, 26 (left). Her friend Kim Bo-hee, 24, said that after months of protests, it was good to have a "day of celebration."
Anger and sadness
At a far smaller rally in support of Park earlier in the day, the mood was strikingly different.
"We impeach the impeachment," a presenter shouted from the stage outside Seoul City Hall.
Demonstrators, many of them in tears, were encouraged to introduce themselves to each other for the "struggle ahead."
Pro-Park Geun-hye rally beginning outside Seoul City Hall now.
Jung Yun-hee, 64, criticized the verdict, saying that it was unfair and not in keeping with the letter of the law. "Even if Park was responsible for mismanagement, she didn't personally profit," she said.
"The freedom of the democracy and the constitution are being threatened," said Kim Jung-hyun, in his 40s.
"There was no reason for the impeachment," Jason Choi, 36, told CNN outside City Hall, where he stood draped in a South Korean flag. "But we will follow the decision of the court."
Both Kim and Choi expressed concern that a potential future left-wing government may reverse the decision to deploy the US-built Terminal High Altitude Area Defense (THAAD), a defensive missile system. The first pieces of THAAD reached South Korea last week.
"The next government must support the security relationship with our friends in the US," Kim said. "We support THAAD deployment because right now North Korea and China are pointing their missiles at us."
Pyongyang weighed in on the impeachment Saturday in an editorial from Rodong Sinmun, a state-run media outlet.
"Park Geun-hye is an ignorant and uncouth dictator who squandered the taxpayer's precious money for her own complacency and pleasure," the piece read. "How pathetic is her wretched life."
Choi said he was worried that the next government would be "China friendly," and would stop the deployment of THAAD, which Beijing opposes.
Park's fate
South Korea's first female President remains in the Blue House, South Korea's executive mansion, for now, despite being ordered to vacate her once childhood home when her father, Park Chung-hee, was President.
Prosecutors are expected to begin interrogating Park as early as Monday on corruption charges, and may seek to block her from leaving the country, according to Korean broadcaster YTN.
The President is accused of being unduly influenced by her longtime friend and adviser, Choi Soon-sil, who is on trial for abuse of power and fraud.
The political career of Park Geun-hye
Former South Korean President
Park Geun-hye leaves an event in Seoul, South Korea, on March 1, 2016. A year later, the country's Constitutional Court
upheld a parliamentary vote to impeach her over allegations of corruption and cronyism. Lawmakers and judges agreed that she abused her authority in helping a friend raise donations from companies.
In this undated photo, Park is seen at back right with her late father, former South Korean President Park Chung-hee; her mother, Yook Young-soo; her sister, Park Geun-young; and her brother, Park Ji-man. Her father seized power in a military coup in 1961. He rewrote the constitution to cement his grip on power and brutally cracked down on dissent and opposition, leading many to call him a dictator.
Park Geun-hye, left, stands next to US President Jimmy Carter during Carter's state visit to Seoul in 1979. After Park's mother was killed in a botched assassination attempt on her father in 1974, Park became regarded as South Korea's first lady.
Park casts a ballot with her father, who was assassinated by his own security chief in 1979. After the loss of her father, Park withdrew from the public sphere, living what she described as "a very normal life."
Park speaks during an interview in May 1999. She said she was persuaded to rejoin politics after seeing the effects of the Asian economic crisis in the late 1990s. She served as a lawmaker in the National Assembly from 1998 to 2012.
Park burns incense at the tomb of her father in August 2012, soon after she was named the presidential candidate for the ruling Saenuri Party.
Park waves to her supporters in November 2012 after making her first official stump speech as a presidential candidate.
Park greets people in downtown Seoul during the launch of her presidential campaign in November 2012.
In December 2012, Park participates in a televised presidential debate with United Progressive Party candidate Lee Jung-hee and Democratic United Party candidate Moon Jae-in.
Park speaks to the media in December 2012 after becoming president-elect.
Park was sworn in as South Korea's first female president in February 2013.
Park arrives for a dinner at the presidential Blue House following her inauguration in 2013.
Park shakes hands with US President Barack Obama during a White House news conference in May 2013.
Park talks with families of missing passengers after the Sewol ferry disaster in April 2014. The passenger ferry sank a day earlier, killing 304 people. Most of those aboard were high school students on a field trip to Jeju island, off South Korea's southern coast.
Park sheds tears as she addresses the nation on the
Sewol ferry disaster in May 2014. Park was criticized for her handling of the tragedy as it became apparent during the investigation that the ferry's sinking was a man-made disaster.
After the corruption allegations surfaced, demonstrators carry cutouts of Park during a December 2016 rally calling for her to step down.
Park speaks to a select group of reporters at the Blue House in January. Park rejected accusations of corruption and refused to step down.
A Park supporter holds up her portrait during a March rally opposing her impeachment.
Anti-Park protesters carry an effigy of the ousted president as they march toward the Blue House in March. Stripped of her immunity, Park is now liable to prosecution and must vacate the Blue House.
The Constitutional Court agreed with accusations that Park had abused her authority in helping Choi raise donations from companies for foundations she had set up.
An election for Park's replacement must be held within 60 days, and an ad-hoc cabinet meeting will be held soon, a government official told CNN.
Experts predict the election will take place May 9.
Sculptures depicting ousted South Korean President Park Geun-hye and acting President Hwang Kyo-ahn at a protest camp on Gwanghwamun Square.
With Park's ruling conservatives looking out of favor, it seems likely the country will turn to the left-wing opposition, which has signaled it would be likely to pursue a policy of engagement with North Korea, as opposed to the more hard line position offered by Park and her conservative allies.
Liberal candidate Moon Jae-in, of the opposition Democratic United Party, currently leads the opinion polls. Moon was defeated narrowly by Park in the 2012 presidential election.
"Korea will start again based on this new and surprising experience," Moon said in a statement on his Facebook page.
CNN's Paula Hancocks, Euan McKirdy, Stella Kim and journalist Taehoon Lee contributed to this report