The United Nations Command has found that a recent explosion in the Demilitarized Zone between the two Koreas constituted a violation of the armistice agreement, reports said.

The blast, which involved four mines, was investigated by the UN Command, which monitors compliance with the 1953 armistice that halted the Korean War. Investigators concluded the incident breached the agreement governing the heavily fortified buffer zone.

North Korea rejected the finding. Kim Yo Jong, the powerful sister of leader Kim Jong Un, dismissed the investigation as a “farce”, according to reports.

The 4-km-wide DMZ remains one of the world’s most militarised borders, lined with minefields, guard posts and fences. Incidents in the zone are rare but carry high escalation risks given the lack of a formal peace treaty between the two sides.

Tensions on the peninsula have remained elevated, with the North continuing weapons development and the South and its allies holding regular military drills. The UN Command’s findings add a fresh diplomatic flashpoint to the strained relationship.