Main opposition presidential candidate Yoon Seok-youl was set to visit the liberal stronghold of Gwangju on Wednesday to apologize for remarks seen as praising a former authoritarian president accused of bloodily quelling a democracy uprising in the southwestern city.

The two-day visit to Gwangju, 329 kilometers south of Seoul, comes about three weeks after Yoon raised the ire of voters there by claiming many people believe former President Chun Doo-hwan did well in politics, except for his bloody crackdown on democracy activists in Gwangju in 1980 and his seizing power through a coup the previous year.

Yoon of the main opposition People Power Party apologized for the comments at the time, saying he only meant to highlight his intention to appoint professionals and draw on their expertise during his administration.

But the apology backfired when his campaign posted a photo of his dog with an apple on Instagram, leading to intense criticism that he likened the people to a dog. In Korean, "apple" and "apology" are homonyms.

Yoon initially considered visiting Gwangju at the start of this month but postponed the trip until after the end of the PPP primary last Friday.

In Gwangju, Yoon is scheduled to visit a national cemetery to pay his respects to the victims of the pro-democracy uprising and meet with their family members.

The crackdown left more than 200 dead and 1,800 others wounded, according to conservative official data.

Yoon is also expected to offer another apology and issue a message of national unity. Some civic activists have vowed to protest his visit.

On Thursday, Yoon plans to travel to liberal landmarks in Mokpo, the main support base of late former President Kim Dae-jung, and Gimhae, where late former President Roh Moo-hyun is buried. (Yonhap)