Editor's note: this story was translated from the original VOA Korean article.
The U.S.-led United Nations Command this week determined that North Korea violated the 1953 armistice agreement with South Korea, after landmine explosions injured three South Korean soldiers inside the Demilitarized Zone. Investigators found an operational North Korean mine south of the Military Demarcation Line, the dividing line established under the 1953 Korean War armistice.
South Korea’s military subsequently concluded that deliberately planted North Korean mines caused the September 21 explosions. It cleared the identified minefield on October 5 and said it would continue clearance operations unless North Korea removed the mines itself.
Pyongyang denies responsibility. In an October 6 statement carried by its state news agency, North Korea’s Foreign Ministry warned of a forceful response if South Korean troops crossed into territory Pyongyang considers its own.
The dispute combines an immediate safety threat with longstanding differences over how the boundary’s precise location is identified.
What happened?
The explosions occurred on September 21 in the western DMZ near Paju, in an area controlled by South Korea’s 25th Infantry Division.
South Korea soldiers were opening a reconnaissance route to allow the United Nations Command to investigate an area suspected of containing North Korean mines.
The first explosion occurred as the soldiers withdrew. A second followed during efforts to rescue the wounded.
South Korea’s military said two soldiers sustained serious injuries, and one suffered minor injuries.
What did investigators find?
South Korea’s Joint Chiefs of Staff announced its final findings on October 5, following a joint field investigation with United Nations Command conducted from September 26 to 29.
The military cited three main types of evidence – the location of the sites, the placement of the mines, and the remnants of the exploded mines.
GPS measurements placed both explosion sites and the recovered North Korean mine about 10 meters south of the Military Demarcation Line, according to the South Korean military’s account of the joint investigation.
Investigators found buried mines and assessed their spacing and the surrounding terrain. Lieutenant General Kwon Dae-won, the Joint Chiefs’ vice chairman, said the United Nations Command assessed that the recovered mine had been deliberately placed. South Korean investigators also concluded that the mines had not simply washed into the area.
Tests by South Korea’s National Forensic Service detected TNT on the wounded soldiers’ clothing and thermosetting resin in fragments recovered from clothing and during surgery. Further analysis found that the fragments matched the material used in previously recovered North Korean plastic antipersonnel mines.
The military said it received the final forensic results on October 2.
Why does the United Nations Command’s finding matter?
The United Nations Command oversees implementation of the 1953 armistice, which halted fighting in the Korean War. The agreement established a buffer zone extending two kilometers on either side of the Military Demarcation Line.
On September 30, the command announced that investigators had found an operational North Korean antipersonnel mine south of the line and determined that an armistice violation had occurred.
It said the violation would be addressed through established armistice mechanisms.
South Korea’s October 5 announcement separately identified North Korean mines as the cause of the explosions. The two findings should be distinguished: the command announced the discovery of a mine and an armistice violation, while South Korea presented its final assessment of what caused the injuries.
Why is the boundary’s location an issue?
Many of the original markers identifying the Military Demarcation Line have deteriorated or disappeared.
South Korea’s military said only about 200 of the original 1,292 markers remain identifiable. Different maps and methods of connecting the surviving markers can produce discrepancies in the line’s precise location.
The military said it uses a reference based on a 2004 map from the U.S. National Geospatial-Intelligence Agency. The United Nations Command uses a reference developed through a 2016 mapping project.
South Korean officials have also said North Korea may use a different interpretation of the boundary.
South Korea’s Defense Ministry said on October 6 that a task force established earlier this year has been working to align the South Korean military’s and the command’s boundary references.
What has North Korea said?
Kim Yo Jong, an official from North Korea's Workers’ Party, rejected responsibility in statements issued on September 30 and October 2.
She described the incident as a South Korean fabrication, threatened retaliation if South Korean forces fired on North Korean troops and dismissed a proposal for communication over identifying and measuring the boundary.
North Korea’s Foreign Ministry reiterated the denial on October 6, according to North Korea's state-run Korean Central News Agency.
It said Pyongyang would not concern itself with South Korea’s removal of mines that North Korea maintained were unrelated to it. But it warned of an immediate, forceful response if South Korean troops crossed into territory Pyongyang considers its own.
What has South Korea done, and what could happen next?
South Korea’s military said it cleared the identified minefield at 12:51 p.m. on October 5.
It said the operation was coordinated with the United Nations Command and conducted with precautions against further accidents or an unintended military clash.
Seoul has demanded an apology for the soldiers’ injuries and called on Pyongyang to remove mines installed in violation of the armistice. The military said it would continue clearance operations if North Korea did not remove them voluntarily.
On October 6, South Korea’s Defense Ministry said it was considering additional responses to press North Korea for an apology, without disclosing specific measures.
Any further clearance operations would take place amid competing accounts of the incident and differing interpretations of the boundary’s precise location.
South Korea’s military says it will coordinate with the United Nations Command on removing mines south of the line while taking steps to prevent an accidental clash.