South Koreans have staged simultaneous rallies in the capital city Seoul in support and against the country’s scandal-hit president a day before the Constitutional Court is to decide her fate.
Scandal-hit President Park Geun-hye has had her powers suspended since her impeachment by parliament in December.
Thousands of police officers were deployed to Seoul on Thursday to maintain security as demonstrators marched in the streets surrounding the Constitutional Court.
Pro-Park demonstrators gathered near the court to urge it not to uphold the impeachment while those against her gathered at Gwanghwamun Square and called on the court to uphold the impeachment.
Anti-Park protesters said their peaceful protests would turn violent and their "candles will turn into torches" if the court allows the president to remain in office to complete her term.
On Friday, judges will decide whether President Park should be removed from office or allowed to stay. At least six of the eight judges on the bench have to vote to uphold the impeachment.
If the court upholds the impeachment, Park would become the country's first democratically-elected president to be thrown out of office.
South Korea will have to hold a new election within 60 days to pick a new president if the court upholds the impeachment or Park steps down voluntarily.
A potential new president will serve a single five-year term. Park's term was originally set to end in February 2018. However, if the court rules out the impeachment, Park will be reinstated.
Park is accused of violating her constitutional duty by colluding with a friend, Choi Soon-sil, in an influence-peddling scheme in which big businesses made huge donations to their foundations.
South Korea's flagship industrial conglomerate, Samsung, is a main firm entangled in the scandalous scheme. Police arrested the company's vice chairman, Jay Y. Lee, in February. He is accused of bribery and embezzlement.