South Korea's snap presidential election began on Tuesday as voters head to the polls to end the country's six-month-long political vacuum in the aftermath of former president Yoon Suk-yeol's enforcement of martial law.

A total of 43.39 million eligible voters are able to vote from 6:00 am to 8:00 pm on Tuesday at 14,295 polling stations across the country.

As of 1 pm local time, the turnout for the 21st presidential election was tentatively tallied at 62.1 percent, according to data from the website of South Korea's National Election Commission.

It was slightly higher than the 61.3 percent record for the same period in the 2022 presidential election.

The snap election came exactly six months after Yoon made a martial law declaration that shocked the country. He was suspended from duty after being impeached by the parliament in December, and was ousted in April by the Constitutional Court.

The presidential race involves five candidates after two dropped out during the campaign. Key contenders include the Democratic Party's Lee Jae-myung and the People Power Party's Kim Moon-soo.

Lee Jae-myung is a presidential candidate for the second time. In 2022, he lost the presidential election to Yoon by 0.7 percentage point, the narrowest margin in South Korean history.

Kim is a former labor minister in the Yoon administration.

Born in 1985, Lee Jun-seok of the minor Reform Party is the youngest presidential candidate. He was a former PPP leader.

A winner is likely to emerge by around midnight, with the vote count to be completed around 6 am on Wednesday.

After the vote count is completed, the National Election Commission is expected to hold a meeting between 7 am to 9 am on Wednesday to formally approve the results, with the meeting to take around 5-10 minutes.

Since the snap election was caused by a leadership vacancy, the new president's term, without the usual two-month transition period, will begin as soon as the National Election Commission confirms the final voting results, according to South Korean broadcaster KBS World.

During the early voting on May 29-30, 34.74 percent of the 44.39 million eligible voters had cast their ballots.

In the presidential election in 2022, the final turnout was 77.1 percent.