It occurred today (6 March) in Pocheon, a city of about 160,000 people near the border with North Korea.
The incident happened as part of a joint military exercise with the US and South Korean Air Forces.
As reported by Reuters, 15 were left injured with houses and a church also damaged as part of a drill gone wrong.
The fire agency released a statement, revealing that two were left seriously hurt.
Eight 500-pound MK-82 bombs were 'abnormally' released by the KF-16 fighter jet, which landed outside its target zone and caused civilian damages.
The South Korean air force said in a statement to the BBC: "Our KF-16 abnormally dropped eight shells of MK-82 bombs. It landed outside of firing range."
They went on, adding: "We are sorry for the damage caused by the abnormal drop accident, and we wish the injured a speedy recovery."
The air force also explained that it would establish a committee that would work to investigate what happened and work out the level of damage caused as a result.
Residents of Pocheon were unsuspecting before the shock incident (X/sentdefender)
They added that they plan to offer compensation and further steps for victims.
The drills were part of preparations taken by South Korea to work on combat readiness for any potential attacks from their neighbours.
Shells from live firing exercises landing near civilian residences isn't a rarity, though they don't often cause injuries.
It has since been claimed that the accident happened due to a pilot putting the wrong coordinates in, according to an official that spoke to Reuters, and chose to remain anonymous.
They explained that two jets dropped four bombs each, with all of them detonating.
Authorities had suspended live-fire exercises until they knew what had gone wrong, though this will not delay the scheduled US and South Korean military exercises that are due to begin this coming Monday, according to the official.
The incident comes after years of protests from residents about the disturbance and potential dangers of being in close proximity to the training grounds.
Videos and photos shared on social media revealed the extent of damage caused, with a house left hollowed out by the impact.
Debris can be seen flying around following the explosions (X/sentdefender)
A 60-year-old resident who was driving when the explosion happened explained that they had shrapnel lodged into their neck, recalling to local outlet Yonhap: "I was driving when I heard a 'bang',
"When I woke up, I was in an ambulance."
Another spoke to the media outlet, saying it was 'like a thunderclap' that shook at their home.
The director of a senior citizen care centre in the area said that the windows had shattered, with one teacher taken to hospital, though no seniors were harmed.
