South Koreans are voting in snap presidential elections to choose a successor to Park Geun-hye, who was ousted from power over a huge corruption scandal in March.
More than 139,000 polling stations opened across the country at 6 a.m. local time (2100 GMT) on Tuesday. Voting is scheduled to close at 8 p.m. (1100 GMT).
The turnout is expected to hit a record high as many voters are angered by the corruption scandal, which rattled both the government and business elite amid the country’s slowing growth and high unemployment rate.
The vote will end a months-long leadership vacuum in the country. Ousted Park, 65, is accused of colluding with her friend, Choi Soon-sil, to pressure big businesses, including Samsung, to contribute huge sums to non-profit foundations that were set up to back up her initiatives.
On March 10, the Constitutional Court ruled to remove Park from office after she was impeached in December 2016.
Later that month, she was jailed over the charges and was officially indicted in April. She has apologized for putting trust in her imprisoned friend, but has denied that she ever broke the law.
Currently, 13 hopefuls are competing to become the Asian country's next president.
On May 4, hundreds of thousands of South Koreans cast their ballots in early voting.
Opinion polls have shown that Moon Jae-in of the liberal Democratic Party would be in the lead.
The final Gallup Korea survey before a week-long pre-election blackout gave him 38 percent support, with former tech mogul Ahn Cheol-soo lagging behind with 20 percent.
“I feel the people’s strong will to change the government... We can make it a reality only when we vote,” Moon said after casting his ballot at a voting station in western Seoul.
The election comes amid increased tensions with North Korea over its nuclear and missile programs.
Hong Joon-pyo, of Park’s Liberty Korea Party, who came third with 16 percent, called on voters to back him, branding Moon “a pro-Pyongyang leftist.”
64-year-old Moon, who has called for negotiations to defuse tensions over North Korea, is believed to favor more independence in ties with Washington.