South Korea Says North Korean Mines Behind DMZ Blast Violated Armistice

South Korea on Tuesday said the explosion inside the Demilitarized Zone (DMZ) last week was highly likely caused by land mines laid by North Korea and said the incident would constitute a violation of the 1953 armistice agreement.

Defence Minister Kang Shin-chul told a parliamentary defence committee meeting that North Korea was responsible if the military's preliminary findings are confirmed. He said South Korea would take “corresponding measures” in response.

South Korea’s military had said on Monday that North Korean land mines were highly likely to have caused the blast after an on-site investigation and forensic examination of fragments and other evidence.

The explosion, near the Military Demarcation Line in Paju, injured two South Korean soldiers seriously and another with minor injuries. The blast occurred as troops returned from a route-clearing operation inside the DMZ.

What The Probe Found

South Korean troops and the United Nations Command conducted a joint survey of the area on Sunday, but initially could not reach the exact blast site because of the risk posed by additional mines and operational constraints.

The team returned to the area on Monday for a further investigation. South Korea's Joint Chiefs of Staff said forensic analysis found brown residue without metal fragments or shrapnel, which it said indicated that South Korean mines were unlikely to have caused the blast.

The military also cited witness accounts that a brown North Korean resin anti-personnel mine had been seen about one metre from the main explosion site. Officials said the crater, flame patterns and injuries were also consistent with a North Korean land mine.

The military has described its finding as preliminary and said North Korean responsibility will be established after the final investigation.

Why The Armistice Matters

The DMZ was established under the Korean Armistice Agreement, which halted active fighting in the Korean War in 1953. Military activities inside the zone are subject to restrictions under the armistice framework.

Kang said on Tuesday that if North Korean mines are confirmed as the cause of the explosion, their placement would constitute an “obvious” violation of the armistice. He said the military had measures available and would implement them in stages.

The issue also comes amid a broader dispute over North Korea’s military activity near the inter-Korean border. A June Yonhap report on a United Nations Command fact sheet said North Korea had carried out land-clearing work, built tactical roads and installed fences and mines north of the Military Demarcation Line since 2024 as part of efforts to fortify its border.

South Korea has argued that some of that work, particularly the construction of fences close to the Military Demarcation Line, violates provisions of the armistice that establish the DMZ as a buffer zone. The UN Command, however, has disputed some of Seoul’s interpretation of North Korean border activity and said investigations were continuing into possible incursions or mine-laying south of the Military Demarcation Line.

The latest blast investigation is therefore taking place against an increasingly fortified border, with South Korea awaiting the final findings before determining its response.