South Koreans turned out in record numbers to cast their ballots as early voting kicked off on Thursday, with long lines at many of the country's polling stations ahead of the June 3 snap presidential election.

South Koreans go to the polls on June 3 to elect the country's 21st president, aiming to restore political stability after months of turmoil and fill a power vacuum following the botched attempt by former leader Yoon Suk Yeol to impose martial law.

In a controversial move, members of a group seen looking for 'Chinese interfernce' while surveying polling booths - Anadolu Ajansı