A former opposition lawmaker's past remarks ridiculing South Korean soldiers who lost their legs in a 2015 bloody land mine explosion are stirring up criticism weeks before the April parliamentary elections. Chung Bong-ju, a Democratic Party (DP) candidate running for Seoul's Gangbuk-B constituency, has come under fire over the comments he made on a YouTube channel in 2017 about the highly publicized incident for which a South Korean probe later concluded North Korea was responsible. The Aug. 4 mine blast happened on the southern side of the Demilitarized Zone (DMZ), separating the two Koreas, near the city of Paju, Gyeonggi Province, when eight South Korean Army soldiers were on a regular scouting mission. The explosion severed the legs of two staff sergeants. The panel on the YouTube channel was talking about ways that the two Koreas could use the ski resorts in the North ahead of the PyeongChang Winter Olympic Games that the South was hosting. Appearing as a guest, Chung said: "We have great stuff in t he DMZ, don't we? Ankle mines. We could all go into the DMZ and give out prizes. Give a set of crutches to each of those who step on the mines." Chung's remarks have come into the spotlight since he won the party primary. In a Facebook post Wednesday, Chung issued an apology over the comments and said he also apologized to the victims over the phone and deleted the YouTube clip. But the soldiers told some local media that Chung has never contacted them, much less given an apology. Mindful of the growing criticism, the DP said it will look into whether Chung told the truth in the Facebook message. "We need to confirm this as the controversy has arisen over the authenticity of his apology," a DP official said. Observers say Chung's candidacy could be at stake if he turns out to be untruthful. Chung, considered to be in the DP mainstream aligned with party leader Lee Jae-myung, won the party ticket for the northern district in Seoul in the primary against Rep. Park Yong-jin, known to be outside the pro-Le e faction. Source: Yonhap News Agency