Tens of thousands of police officers lined the streets of Seoul on Saturday to separate a rally in support of the ousted president, Park Geun-hye, from a larger rival group demanding her arrest.
Carrying flags and candles and cheering jubilantly, tens of thousands of people occupied a boulevard in downtown Seoul to celebrate Ms Park's ouster. Fireworks were let off in what many in South Korea saw as a celebration of democracy at work.
Meanwhile, in a nearby grass square, a large crowd of Ms Park's supporters glumly waved national flags near a stage where organisers, wearing red caps and military uniforms, vowed to resist what they called a "political assassination."
Police had braced for violence between the two crowds after three people died and dozens were injured in clashes between police and Ms Park's supporters, after a constitutional court upheld her impeachment on Friday.
Nearly 20,000 police officers were deployed on Saturday to monitor the protesters, who were also separated by tight perimeters created by hundreds of police buses.
Ms Park was thrown out of office over a corruption scandal involving the country's conglomerates. The 65-year-old is South Korea's first democratically elected leader to be forced from office, and her ouster followed months of political paralysis and turmoil over a corruption scandal that also landed the head of the Samsung conglomerate in jail and facing trial.
The court ruling marked a dramatic fall from grace of South Korea's first woman president and daughter of Cold War military dictator Park Chung-hee. She served as his first lady after the 1974 assassination of her mother. Her father was then gunned down by his security chief in 1979.
And her removal from office has sharply divided the country.
Now, having lost presidential immunity, she could face criminal charges over bribery, extortion and abuse of power in connection with allegations of conspiring with her friend, Choi Soon-sil. Both women denied wrongdoing.
"Impeachment is not the end. We've not dispersed, we're still going forward, united," said one anti-Park protester, who gave his name as T.H. Kim. "She's a citizen now. If she's done something wrong, she has to be arrested."
Ms Park did not appear in court on Friday and did not make any comment after the ruling. She spent the night in the presidential Blue House though would leave at some time and return to her Seoul residence, a spokesman said.
Choi In-sook, a spokeswoman for protesters opposed to Park, told Reuters they were also demanding the resignation of acting president Hwang Kyo-ahn. Prime Minister Hwang, a Park loyalist, became acting president when parliament voted to impeach her on Dec. 9.
Mr Hwang has called for calm and promised that a snap presidential election, which has to be held within 60 days, would be smooth.
But Ms Park's supporters want her to stay in power. Some want the court decision overturned and her case heard again by new judges.
"We strongly request the trial is held again," said Chung Kwang Yong, a spokesman for organisers of rallies backing her.
Leading in opinion polls to succeed her is prominent liberal politician, Moon Jae-in, who advocates reconciliation with North Korea.