Landmines wounded 3 South Korean soldiers in the Demilitarized Zone.

South Korea demanded an apology and vowed staged countermeasures over what it calls an armistice violation.

The UN Command, which investigated on site, identified an active North Korean anti-personnel mine on South Korea’s side of the border.

North Korea denies it, and leader Kim Jong Un’s sister Kim Yo Jong calls the claim groundless.

The UN Command says it will handle the armistice violation through established armistice mechanisms.

Sources: BBC, Deutsche Welle, Reuters