South Korean and United Nations investigators have concluded that two landmines that exploded inside the Demilitarized Zone last month, severely injuring three soldiers, were planted by North Korea, Seoul’s military announced on Monday. The findings, presented by the Joint Chiefs of Staff, align with a preliminary probe indicating that North Korean troops crossed the Military Demarcation Line—an assertion that Pyongyang has rejected.
Forensic Testing Identifies North Korean Plastic Mines
The National Forensic Service conducted several rounds of testing on fragments recovered from the Sept. 21 explosion, which occurred while 18 soldiers from a reconnaissance battalion under the Army’s 25th Infantry Division were clearing a new patrol route. Lt. Gen. Kwon Dae-won, vice chairman of South Korea’s Joint Chiefs of Staff, detailed the results during a briefing at the Ministry of National Defense in Seoul.
The first and second rounds of testing detected TNT, brown foreign material and thermosetting resin components, identifying the device as a North Korean-made plastic anti-personnel mine,
Kwon said.
Kwon noted that investigators compared blast fragments with previously recovered North Korean ordnance, confirming that the materials were identical. Military intelligence authorities assess that the device resembles a resin anti-personnel mine manufactured by North Korea since 1969, making it distinct from the M16 mines utilized by South Korean forces and ruling out remnants from the 1950–53 conflict. Troops operating at the site saw a rectangular plastic mine roughly one meter from the blast craters, and forensic teams also detected trinitrotoluene traces on an injured soldier’s body armor.
North Korea Violated Armistice Agreement by Laying Mines
In addition to the two detonated devices, the investigation uncovered a third, unexploded landmine near the site. This discovery led the South Korean military and the U.S.-led United Nations Command to determine that the placement constituted a direct violation of the Armistice Agreement that has partitioned the peninsula since 1953.
Military officials assessed that the mines were laid approximately a year ago, noting that previous satellite imagery showed North Korean troops conducting fortification work and laying mines across the demarcation line in the area since August of last year. The blast site sat roughly 10 meters away from an established North Korean minefield.
Following the incident—the first time in 11 years that South Korean troops suffered severe injuries from a North Korean mine, following a 2015 wooden box mine incident—Seoul’s military stated it would push forward with mine-clearance operations south of the demarcation line. Kwon urged Pyongyang to immediately remove the remaining explosives and demanded a sincere apology.
Pyongyang Rejects Responsibility Amid Rising Tensions
North Korea has denied any involvement in the explosions. Kim Yo Jong, the sister of the North Korean leader, dismissed Seoul’s initial demands for accountability, labeling the South Korean government as despicable.
South Korea and North Korea remain technically at war, as the Korean War concluded with an armistice rather than a formal peace treaty.
