Seoul seeks apology after North Korea denies involvement in DMZ explosion

South Korea on Wednesday demanded an apology and "responsible measures" from North Korea after Pyongyang denied its involvement in last week's landmine explosion inside the Demilitarized Zone (DMZ) that injured three South Korean troops, according to media reports.

Seoul's demand came hours after North Korea denied involvement in the Sept. 21 mine blast on the southern side of the heavily fortified border and dismissed the North’s claims as a "groundless" conspiracy," Yonhap News reported.

"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 Joint Chiefs of Staff (JCS), told reporters.

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

"We strongly demand an apology and responsible measures from the North," Kang added.

The UN Command (UNC), which oversees the armistice agreement, said it determined an armistice violation occurred in the DMZ explosion, based on findings from a joint investigation with the South's military.

It did not cite, however, the blast itself as a violation, but pointed to an active North Korean mine discovered Tuesday on the South Korean side of the Military Demarcation Line (MDL) during the joint inspection.

Seoul claims that North Korean resin antipersonnel mines deliberately planted on the southern side of the Military Demarcation Line were highly likely the cause of the blasts.

North Korea denied the allegation, accusing South Korea of fabricating the findings and warning of "immediate and merciless" retaliation if its troops are fired upon.

"What should not be overlooked is the fact that the armed gangsters of the ROK are now cooking up the groundless results and 'justifying their conduct' for political and military provocation against the DPRK, openly talking about 'reasonable and corresponding enforcement of measures," Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, said in a statement carried by the state-run Korean Central News Agency.

DPRK stands for the Democratic People’s Republic of Korea, North Korea’s official name, while ROK stands for the Republic of Korea, South Korea’s official name.

Kim stressed that North Korean soldiers "have never crossed the border" while accusing the South Korean military of threatening its soldiers with warning broadcasts and 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," she said.