Kim Yo-jong rejects Seoul's DMZ mine accusations, warns of ‘merciless’ retaliation

North Korea on Wednesday denied involvement in a recent explosion at the inter-Korean border, accusing Seoul of making false accusations while warning of "immediate and merciless" retaliation if South Korean troops open fire on its soldiers working near the border.

The unusually swift warning from Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un and a department director of the Workers’ Party of Korea Central Committee, came after South Korea's Joint Chiefs of Staff said North Korean mines were "highly likely" to have caused the Sept. 21 explosion. The incident left three South Korean soldiers injured, two critically.

But analysts noted that Pyongyang's military warning was directed not at the western section of the DMZ where the explosion occurred, but toward the eastern front, where North Korea has been carrying out extensive work to fortify the inter-Korean border.

The distinction suggests Pyongyang may be seeking not only to reject responsibility for the two successive blasts, but also to protect its ongoing border construction and deter Seoul from taking measures that could interfere with the work, experts said.

In a statement carried by the Korean Central News Agency in English, Kim accused the South Korean military of "cooking up the groundless results" to justify what she described as political and military provocations against North Korea.

Kim said North Korean troops carrying out what Pyongyang calls its project to permanently fortify its southern border "have never crossed the border," accusing the South Korean military of threatening the soldiers with warning broadcasts and warning shots.

"If the ROK military gangsters fire at our soldiers carrying on the permanent project for the southern border, not warning shots, our border units will take immediate and merciless retaliate attack," Kim said, referring to the South's official name, the Republic of Korea.

She also said the North Korean military had decided to "increase the tactical counterattack means" in the direction of South Korea's 21st Infantry Division under the III Corps and had issued counteraction guidelines to its border defense units.

The 21st Infantry Division, however, is stationed along the eastern front, while the Sept. 21 mine explosion occurred in the western section of the DMZ in an area involving the South Korean Army's 25th Infantry Division.

Hong Min, a senior research fellow at the Korea Institute for National Unification, said the geographical discrepancy is significant because the area facing the 21st Infantry Division is a focal point of North Korea's ongoing border fortification work.

North Korea's immediate concern may therefore be less about the mine incident itself than about preventing Seoul's response to the explosion from disrupting its border construction or putting North Korean personnel working there at risk, according to Hong.

"The incident is in the west, while the warning is directed toward the east," Hong said in an analysis of Kim's statement.

Pyongyang has been reinforcing barbed wire, laying mines and erecting anti-tank barriers along the Military Demarcation Line since 2024 as part of efforts to physically sever connections with South Korea.

Lim Eul-chul, a professor at Kyungnam University's Institute for Far Eastern Studies, said Pyongyang appears intent on portraying South Korean warning shots and other actions near the border as interference with what it regards as legitimate exercises of sovereignty.

"By doing so, North Korea could seek to establish a justification in advance for retaliation should a miscalculation or exchange of live fire occur along the heavily fortified border," Lim said.

"The warning could also be intended to place psychological pressure on South Korean military commanders and policymakers, potentially discouraging them from taking measures such as warning broadcasts or warning shots near North Korean construction sites," he added.

The heightened rhetoric came as the South Korean military issued its first official message directly addressed to Pyongyang over the Sept. 21 explosion.

The JCS on Wednesday demanded that North Korea apologize and take "responsible measures," while calling on Pyongyang to immediately halt border activities that raise military tensions.

"This constitutes a blatant violation of the Armistice Agreement and undermines the spirit of existing inter-Korean agreements and must be halted immediately," Lt. Gen. Kang Hyun-woo, chief director of operations at the JCS, said at a press briefing.

"North Korea must immediately cease activities that heighten tensions on the Korean Peninsula, such as its so-called 'border fortification.' We strongly demand an apology and responsible measures from the North," Kang said.

"We make it explicitly clear that North Korea bears full responsibility for any future consequences that may arise," he added.

South Korea's military said its preliminary investigation found that North Korean resin antipersonnel mines deliberately planted south of the MDL were highly likely to have caused the explosion.

The UNC separately concluded that the explosion constituted an Armistice Agreement violation, while a joint investigation with the South Korean military identified an active North Korean mine south of the MDL.

Hong said Kim's swift intervention — just a day after the JCS announced its preliminary findings — elevated the dispute beyond a working-level military exchange and reflected Pyongyang's increasingly assertive posture.

At the same time, he noted that Kim explicitly tied retaliation to actual gunfire against North Korean troops or an infringement of what Pyongyang considers its territory, without identifying warning broadcasts or warning shots as triggers. The distinction could signal an attempt to set a threshold for retaliation while keeping room to manage escalation, he said.

Lim warned, however, that North Korea's reinforcement of "tactical counterattack means" near the border could increase the risk of an accidental clash. He called for heightened surveillance and carefully managed rules of engagement, as well as efforts to restore inter-Korean military communication channels to prevent unintended escalation.