South Koreans can begin casting their ballots during the preliminary voting period for the April 13 parliamentary elections later this week, the state election office said Thursday.

The preliminary voting will kick off on Friday for a two-day run at 3,511 polling stations across the country, the National Election Commission said.

Voters are required to carry a valid form of photo identification and visit a nearby polling station between 6 a.m. and 6 p.m., the NEC said.

The NEC additionally set up polling stations at public facilities such as the country's main gateway, Incheon International Airport, and two main train stations in central Seoul.

The commission first adopted the system during the April by-election in 2013 as part of its effort to boost the voter turnout rate. (Yonhap)