Joint Chiefs: DMZ explosion occurred during trail-clearing operation, all causes under probe

South Korea's Joint Chiefs of Staff said Monday that the cause of an explosion involving an Army 25th Division unit inside the Demilitarized Zone had yet to be determined and that investigators were keeping all possibilities open.

A Joint Chiefs spokesperson told reporters that two injured officers had been airlifted and were receiving treatment at the Armed Forces Capital Hospital. The spokesperson added that one additional soldier, along with others who took part in the operation, would be transported to the same hospital for thorough medical evaluations after triage — leaving open the possibility that the total number of casualties could rise beyond three.

One of the injured officers was undergoing surgery after suffering a severed ankle, sources said. The other sustained separate injuries and was also receiving treatment. When asked whether the soldiers had been wearing protective gear, the spokesperson said only that the matter would be checked.

The explosion occurred at around 10:50 a.m. Monday inside the DMZ on the western front. The spokesperson said the site was located between the Military Demarcation Line and the Southern Limit Line, but declined to give a more precise location, citing operational security.

Asked about speculation that North Korean forces had laid mines south of the MDL, the spokesperson said the incident did not occur in an area where previously noted terrain changes had been observed and that the site was some distance from that zone. The exact distance was not disclosed.

The spokesperson described the operation as a trail-clearing mission conducted as part of a DMZ search operation, undertaken in response to terrain changes — such as overgrown vegetation that had obscured existing pathways — that required new routes to be established. Asked whether the operation was specifically aimed at countering North Korean mine-laying activity, the spokesperson said the specific purpose of the mission could not be disclosed.

Three possible causes remain under consideration. The spokesperson flatly denied that an exchange of fire between the two Koreas was involved, saying it was not a shooting incident.

Investigators will examine whether the mine was South Korean, a North Korean mine that had drifted from its original position, or one deliberately planted by North Korean forces, the spokesperson said, adding that all possibilities would be investigated.

On whether a mine was responsible, the spokesperson said it was currently an assumption but that a land mine explosion appeared most likely. The spokesperson also said the blast was not heard multiple times. The United Nations Command is expected to participate in the investigation.

During the evacuation, a medevac helicopter entered the DMZ with UN Command coordination. The spokesperson said the injured could not all be evacuated at once and were transported sequentially based on the severity of their injuries. Given the emergency and the safety of the soldiers, the spokesperson said, it was a clear judgment call to bring the helicopter in with UN Command's cooperation. One soldier was moved by ground before being airlifted — not because of a shortage of helicopters, the spokesperson said, but because ground transport was feasible given that person's condition. The UN Command was notified of the situation, and no unusual activity was observed from North Korean forces.

The spokesperson said no timeline could be given for when the investigation's findings would be announced.