Military knew of suspected NK mine-laying a year before DMZ blast

South Korea’s military identified suspected North Korean mine-laying activity south of the Military Demarcation Line (MDL) and reported it to senior defense officials a year before an explosion injured three soldiers, documents released during a parliamentary audit showed Wednesday.

According to documents the Joint Chiefs of Staff (JCS) submitted to Rep. Yu Yong-weon of the main opposition People Power Party, satellite imagery collected on Sept. 23, 2025, showed suspected mine-laying south of the MDL in the Army’s 25th Division sector. The initial analysis described the area as a “suspected mine-laying section.”

The assessment was reported in person to then-JCS Chairman Jin Young-seung the following day. Then-Defense Minister Ahn Gyu-back, who was overseas, received a text message on a secure phone and was briefed again after returning. The reports also warned of possible further MDL incursions.

Three soldiers were injured on Sept. 21 while clearing a new search route for a United Nations Command (UNC) field inspection in the Demilitarized Zone (DMZ). Following a joint investigation with the UNC and forensic analysis, the military concluded on Monday that a plastic antipersonnel mine planted by North Korean troops south of the MDL caused the blast.

“The military must explain what measures it has taken since learning a year ago that North Korea’s minefields may have extended into our territory, and why it did not properly explain this to the public,” Yu said.

He accused the military of downplaying the threat as “terrain changes” when he raised concerns last month. The JCS said then that it was consulting the UNC about possible mine-laying, but had not confirmed whether mines were present.

At the audit, Defense Minister Kang Shin-chul acknowledged the possibility of more North Korean mines south of the MDL.

“We also see grounds for that assessment,” Kang said when Yu suggested hundreds of mines could remain, based on North Korea’s mine-laying patterns and the extent of its incursions.

Asked whether areas outside the 25th Division’s sector were also suspected of containing mines, he said there were “several locations.”

“We will conduct joint investigations with the UNC to establish the facts and continue taking the necessary measures,” he said.

North Korea on Tuesday dismissed the investigation as a fabrication and threatened a strong response to any intrusion into its territory, “even by 1 millimeter.”

Kang said Pyongyang’s delayed response suggested it had been “considerably taken aback” by Seoul’s actions. He also denied that the South's DMZ operations had been scaled back.

Separately, Kang addressed military service benefits for athletes and artists.

“Our ministry’s goal is to gradually reduce military service exemptions and ultimately abolish them,” he said. The issue resurfaced after some players on the Asian Games gold medal-winning football team celebrated avoiding military service. Kang said he “deeply regretted” their remarks and actions.

Under the current system, Olympic medalists and Asian Games gold medalists who qualify for military service exemption undergo basic military training and serve as sports personnel rather than active-duty soldiers.

In the arts, exemptions cover classical music, dance and "gugak" (traditional Korean music), with eligibility granted for those winning second place or above at a designated international competition, or first place at a domestic competition. Those who place highly enough qualify for transfer to arts personnel status in lieu of active-duty service.

Smart glasses, connected cars raise security concerns

The defense ministry was also asked about security risks at military facilities. Rep. Chun Ha-ram of the Reform Party said he entered the defense ministry wearing Chinese-made smart glasses and driving China's BYD electric vehicle without being stopped.

He warned that connected cars equipped with cameras and GPS and linked to the internet could expose sensitive information at military facilities, urging tighter safeguards for both vehicles and smart glasses.

“We recognize the problem and will take action,” Kang said. He said the ministry was considering restrictions on bringing such devices onto military premises and using artificial intelligence to identify information-gathering devices and potential security threats in advance.