The military, which launched its on-site investigation six days after the explosion, now bears responsibility for determining the cause of the suspected land mine blast in the Demilitarized Zone and dispelling a range of suspicions. Opposition lawmakers have focused on why the probe was delayed, the risk that evidence has been lost, and allegations of discord between South Korean forces and the United Nations Command.
The on-site investigation by the Joint Chiefs of Staff and the U.N. Command, which began on the 27th, involved about 40 people, including South Korean operational troops, U.N. Command personnel such as the secretary of the Military Armistice Commission, and officials from investigative agencies. Some officers who were carrying out the operation when the accident occurred on the 21st also joined the probe. The Joint Chiefs said, "South Korean forces and the U.N. Command today jointly approached the vicinity of the presumed site of the explosion in connection with the suspected land mine blast inside the DMZ."
The team, however, is said to have been unable to reach the presumed blast site itself, meaning that work to collect mine fragments and other debris left at the scene was not carried out. Securing fragments at the site is expected to provide a key clue to determining whether the explosive was a North Korean mine or a South Korean one. The Joint Chiefs said it "plans to thoroughly determine the cause of the accident through further investigation and to transparently explain the facts that are confirmed."
Through additional investigation, the team intends to focus on identifying the specifications of the mine that detonated. The most sensitive question is whether it was a North Korean mine. After declaring the two Koreas "two hostile states" in 2023, North Korea has been fortifying the border, laying mines along the Military Demarcation Line and building tactical roads and barriers. If the mine behind this explosion is confirmed to have been laid during that process, it could constitute a violation of the armistice agreement, making a response from the South Korean government unavoidable.
Opposition lawmakers have argued from the earliest stage of the accident that a North Korean mine was the likely cause. They point out that the M14 anti-personnel mine typically used by the South Korean military is unlikely to cause the kind of serious injuries seen in this case when protective gear is worn. For that reason, North Korea's more powerful wooden-box mines have been cited as the probable cause. The accident site, however, is several dozen meters away from the area where North Korea is believed to have laid mines. Given a previous case in which a North Korean mine washed away by torrential rain was found on the coast of Ganghwa County in Incheon, the possibility that it was a stray mine cannot be ruled out.
The Joint Chiefs had already secured items including the injured soldier's mine-protection overshoes and other gear, gauze used to collect gunpowder residue, and fragments removed during surgery, and on the 22nd requested component analysis from the National Forensic Service. Initial findings are expected this week. Items newly found during the on-site investigation will also undergo detailed analysis.
Political attacks over the risk that evidence was lost because of the delayed investigation have continued. People Power Party members of the National Assembly's Foreign Affairs and Unification Committee held a news conference on the same day, saying, "As time passes and rain falls, the site is damaged and it becomes difficult to determine the exact cause." They added, "Are you perhaps afraid that it will turn out to be North Korea's doing?"
The Joint Chiefs has countered that the priority was safety measures to prevent a second accident, not a delay in the probe. It said the area is "extremely dangerous, because our operational troops were using mine detectors to clear a search route for the first time when the explosion occurred." The explanation is that the risk of another blast is high because the area is not a standard search route and is covered with vegetation grown to an adult's waist height. The Joint Chiefs said the U.N. Command also agrees that thorough safety measures must come first and is cooperating. On the 26th, the previous day, the Joint Chiefs disclosed that it had begun securing access routes and surveying the operational environment, and in an unusual step also released video footage from the site.
The "discord controversy" between South Korean forces and the U.N. Command has also become a point of contention. On the 25th, the Joint Chiefs said, "The U.N. Command's Military Armistice Commission visited the 25th Division on the 22nd to confirm the circumstances of the explosion and related details, and coordinated matters concerning a joint on-site investigation with our military." It added that "claims to the effect that our military dragged its feet in response to the U.N. Command's request for an investigation are also not true."
Han Dong-hoon, an independent lawmaker on the Foreign Affairs and Unification Committee, countered that the U.N. Command had requested access to documents, body-camera footage and interview records with the injured, as well as entry to the site, but that the South Korean military refused. The Joint Chiefs directly rebutted Han's claim, stressing that cooperation with the U.N. Command had been continuous, including a preliminary survey on the 26th and the on-site investigation on the 27th.
The Joint Chiefs also expressed concern that Han had disclosed the on-site investigation schedule, which it said constitutes military secrets. "Operational plans such as the on-site investigation schedule are security matters, and if exposed they could pose a grave threat to the safety of our troops and the investigation team," it said.
Meanwhile, Jin Sung-joon of the Democratic Party of Korea, chairman of the National Assembly's National Defense Committee, plans to visit the DMZ sector under the Army's 25th Division on the 28th for an on-site inspection. Other committee members are also expected to attend, while People Power Party members of the defense committee called it a "show visit" and said they would not take part.
