Two mines exploded about 10 meters south of MDL; one more found nearby
National Forensic Service detects TNT, brown residue but no metal fragments
![Kwon Dae-won, deputy chief of the Joint Chiefs of Staff, briefs reporters at South Korea's Ministry of National Defense in Yongsan-gu, Seoul, on Monday on the suspected landmine explosion in the demilitarized zone. [Yonhap]](https://wimg.heraldcorp.com/news/cms/2026/09/28/rcv.YNA.20260928.PYH2026092824510001301_P1.jpg)
South Korea's military has effectively pointed to North Korean landmines as the cause of the explosion in the demilitarized zone near Paju, Gyeonggi Province — one week after the incident.
However, the military also said it is difficult to conclude for the time being that the mines were deliberately planted to target South Korean troops, as was the case in the 2015 wooden-box mine provocation. The assessment is expected to fuel debate over how strongly Seoul should respond to Pyongyang.
Deputy Chief of the Joint Chiefs of Staff Kwon Dae-won, who heads the on-site investigation TF, announced the interim findings Monday night.
"The probability is very high that the mines that exploded were North Korean," Kwon said. "If that is the final determination, all responsibility lies with North Korea, and we will take appropriate and commensurate measures."
The explosion occurred about 10 meters south of the Military Demarcation Line, also roughly 10 meters from an area where terrain changes suggest North Korean mine-laying activity. Two mines detonated, and a witness statement that one more was spotted during the withdrawal led investigators to conclude that three mines were present in total.
The key evidence came from analysis by the National Forensic Service, which examined 10 items including clothing, gear and gauze swabs used to collect explosive residue. Trinitrotoluene (TNT) and a brownish foreign substance were found on one ballistic helmet and two bulletproof vests, but no metal fragments were detected.
Yang Jin-hyeok, director of operations at the Joint Chiefs, said the absence of metal fragments ruled out South Korean mines. "Our mines use TNT as the main charge and produce large quantities of metal fragments, with a lethal radius of more than 20 meters," he said.
A Joint Chiefs official added that M14 mines do not contain TNT, and that an M16 would have caused far greater casualties.
The existence of a third mine came to light during the evacuation after the blasts. A combat engineer crawling on his knees and probing the ground with a hand pick found a square-shaped object at a depth of 5 to 10 centimeters, about 1 meter from the site of the first explosion, after covering 20 meters of ground.
The engineer described it as "smooth brown plastic." The military assessed it to be a North Korean resin anti-personnel mine — identical in shape to the wooden-box mine but made of plastic. Witness accounts varied, however, with some describing it as red, others as brown, and others likening it to a wooden-box mine.
Questions over the failure to detect the mines are unavoidable. The mines were located at the end of a search path that combat engineers had swept with detectors, and the explosions occurred in a section that had already been cleared. A Joint Chiefs official said engineers may have treated years of accumulated brush and undergrowth as topsoil, placing the mines at a depth beyond the reach of the detectors.
The sequence of events at the moment of the explosion was also disclosed for the first time. The battalion commander had ordered a withdrawal after judging that the unit was approaching the MDL. As a combat engineer took a step while preparing to pull back, the first explosion occurred. The battalion commander ran toward the fallen soldier shouting "Are you OK?" when a second explosion went off nearby. A listening device at a guard post about 800 meters away recorded the two blasts 58 seconds apart.
The military withheld judgment on when the mines were planted and whether they were placed intentionally. "The one mine that was found appears to have been deliberately buried, but the timing of the two that exploded requires further investigation, and the possibility that they drifted to their location cannot be ruled out," a Joint Chiefs official said. The official added that, unlike the 2015 incident — in which mines were planted on either side of a gate — this explosion occurred at a point the South Korean military had newly opened up, making it difficult to conclude that the mines were intended to target South Korean troops.
Differing interpretations of where the MDL lies are also a factor. A Joint Chiefs official noted that North Korea uses a Soviet-era coordinate system while South Korea uses the World Geodetic System, and that the UN Command uses yet another reference, meaning North Korea may have regarded the location as its own territory. The military identified terrain changes via satellite imagery from last September and estimated that North Korean troops carried out work in the area between last August and November. No North Korean troop movements were directly observed.
The military also corrected an earlier statement. On Wednesday, it had described the distance between the explosion site and the suspected mine-laying area as "tens of meters"; on Monday it revised that figure to about 10 meters. A Joint Chiefs official attributed the discrepancy to location-reporting errors caused by poor communications reception in the area.
On criticism that the on-site investigation had been delayed, Yang drew a line. "This is not a matter of will — it is a matter of ensuring the thorough safety of our troops," he said.
On Monday, a team of about 40 investigators entered to within 2 meters of the second blast site, confirmed two craters, and recovered a military pack, a ballistic helmet and mine-resistant boots.
On the question of next steps, Yang said the military would "put all necessary military and policy options on the table and make its judgment."
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