North Korea denies South's claim it was behind DMZ blasts

South Korea's military has demanded an apology from North Korea, blaming Pyongyang for a 21 September explosion that severely injured three South Korean soldiers inside the countries' Demilitarized Zone (DMZ).

"North Korea must immediately cease activities that heighten tensions on the Korean Peninsula... and we strongly urge an apology and responsible measures," an official from Seoul's Joint Chiefs of Staff told reporters.

It comes after North Korean leader Kim Jong Un's powerful sister denied claims that North Korea was behind the landmine blasts, according to state media.

The assertion over the explosions "is too low and dirty as befitting the tribes of the ROK," Kim Yo Jong said in a statement, the KCNA news agency said, referring to the South's formal name, the Republic of Korea.

One soldier lost a foot due to the 21 September explosions in the Demilitarised Zone, the heavily mined buffer zone that has divided the two Koreas since their 1953 armistice.

It is one of the world's most heavily fortified frontiers and landmine incidents have previously heightened tensions between the two Koreas.

Seoul and Pyongyang remain technically at war since the Korean conflict ended in a truce, not a peace treaty.

After carrying out an investigation into the incident, the South Korean Defense Ministry said it concluded that North Korean mines were "highly suspected" of causing the two explosions.

"This is a clear violation of the armistice agreement, and since North Korea bears responsibility, we will take corresponding measures," South Korean Defence Minister Kang Shin-chul said.

But Ms Kim said the South is "cooking up" bogus allegations as a pretext for political and military provocation against North Korea, KCNA said.

Since 2024, after Mr Kim designated South Korea as his country's "principal enemy," Pyongyang's military has laid mines and built anti-tank barriers along the frontier as part of efforts to permanently seal it off.

During the operation, Pyongyang also blew up the northern parts of inter-Korean roads no longer in use.

Mr Kang said that the North Korean mines linked to the 21 September incident were believed to have been laid as part of Pyongyang's border fortification work.

In a 2015 incident, two South Korean soldiers were seriously wounded in a landmine blast on the southern side of the DMZ, with one losing both legs.

Seoul concluded that North Korean troops had crossed the Military Demarcation Line to plant the mines, an accusation Pyongyang denied.

The incident prompted South Korea to resume anti-Pyongyang loudspeaker broadcasts along the border.