JCS: North Korean mines caused DMZ blast; military clears minefield south of MDL

South Korea's Joint Chiefs of Staff said the Sept. 21 explosion at the western-front Demilitarized Zone was caused by a North Korean plastic anti-personnel mine laid south of the Military Demarcation Line, and that the military removed the North Korean mines in the area on Oct. 5. JCS Deputy Chief Kwon Dae-won, an Army lieutenant general, told a briefing at the defense ministry in Yongsan, Seoul, that the final judgment was that a soldier carrying out normal DMZ operations south of the MDL was seriously injured by a North Korean plastic anti-personnel mine the North had laid under the pretext of what it calls border fortification work. Kwon said the removal operation was conducted at about 12:51 p.m. on Oct. 5. [ 4 , 5 , 7 , 8 , 14 ]

The JCS cited several pieces of evidence. Kwon said the joint on-site investigation team worked with the UN Command from Sept. 26 to 29 and that the announcement was based on the joint field investigation and a National Forensic Service appraisal received on Oct. 2. He said additional North Korean plastic anti-personnel mines were found during the final investigation on Sept. 29, along with first and second explosion points nearby, and that GPS confirmed three points about 10 meters south of the MDL, which the UN Command judged an armistice violation. Kyunghyang Shinmun reported that fragments from the injured soldier's gear and surgery matched North Korean plastic anti-personnel mines previously collected at the Imjin River, that a discovered mine was buried about 3 centimeters deep with unexploded mines 1 to 2 meters from the crater, and that the emplacement appeared to have occurred more than 12 months earlier. Dong-A Ilbo reported that North Korea had called the incident a self-staged provocation, and that the conclusion came two weeks after the explosion. [ 7 , 8 , 14 , 20 ]

The JCS said the problem extends beyond the explosion site. Kim Sung-yun, head of the JCS intelligence analysis division, said suspected North Korean mine-planting areas were identified at several locations south of the MDL, with an average incursion of about 20 meters, according to Kyunghyang Shinmun and Dong-A Ilbo; Yonhap also reported several suspected areas averaging about 20 meters south of the line. Kim said North Korean MDL violations were identified nine times in 2024, 17 times in 2025 and about 50 times this year, and that at one site patrols about 10 meters south of the line have repeated more than 40 times. Dong-A Ilbo reported that in some areas the North has installed barbed-wire fencing south of the MDL, and that the military plans joint verification with the UN Command. Kwon said clearing operations south of the MDL will continue unless North Korea removes the mines itself, and demanded an apology for the injured soldiers. [ 4 , 8 , 12 , 14 , 19 ]

Kwon said the operation was conducted in close coordination with the UN Command, with measures to comply with the armistice and prevent accidental clashes. Kyunghyang Shinmun reported that the military notified North Korea of the relevant facts through the UN Command and broadcast several warnings before the operation, that North Korean troops were seen observing the explosion point but showed no particular movement, and that the military did not disclose the removal method or the number of mines cleared. Kyunghyang Shinmun described the action as the first military response to the incident, and Yonhap reported it as the first step in a response, with attention on further measures toward the North. [ 4 , 9 , 14 , 15 ]

On Oct. 6, Defense Minister Kang Shin-chul told reporters at the defense ministry that the operation was “the first of its kind in our DMZ history” and that he regarded it as a stern response, saying the military had taken the necessary measures. He said all responsibility lies with North Korea and that the military will respond sternly to any act harming national security. Asked about criticism that the response was too passive and defensive, he said that was not the case. Kang also said that to verify matters such as the MDL baseline, the two sides would have to come to the field or to a table, leaving open the possibility of dialogue while watching the North's next moves. [ 21 , 22 , 23 , 24 , 25 , 26 ]

Kyunghyang Shinmun reported that the border fortification work began in April 2024, involving minefields, tactical roads, barbed wire and anti-tank barriers along the MDL, and that the military expects it to be completed across the entire MDL within two years. Hankook Ilbo published an editorial arguing that the removal of North Korean mines in the DMZ was warranted and that appropriate corresponding measures should continue. Asia Economy's article framed the announcement against heightened inter-Korean tension, saying dialogue has long been severed, the North has been firing missiles in shows of force while the South responds strongly, and referring to a bell of hope hung at a barbed-wire line near the northernmost civilian control line. [ 3 , 14 , 16 ]