South Korea has said it will respond firmly to protect its military border with North Korea, as tensions along the heavily guarded frontier continue to rise. The warning came on Friday from Seoul's national security adviser, Wi Sung-lac, who said the country would defend the border line despite claims from Pyongyang that its activity is taking place on its own side.

The latest strain follows a landmine blast inside the Demilitarised Zone last month that seriously wounded several South Korean soldiers on a reconnaissance mission. Seoul has said the mine was North Korean. The United Nations Command, which oversees the zone, has said a North Korean mine placed across the line breached the armistice that ended fighting in the Korean War.

A dispute over fortification work

Seoul has demanded that Pyongyang immediately stop fortification work near the border, arguing that the activity has raised tensions in an already fragile area. North Korea has denied responsibility for the mine blast, and the two sides remain far apart on what happened and who should act first.

The row has also revived one of the peninsula's oldest forms of psychological warfare. Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, said on 21 October that the North would switch on anti-South Korean propaganda loudspeakers along the entire border by the end of October.

No broadcasts yet, Seoul says

South Korea's intelligence agency said on Thursday that those broadcasts had not yet begun. Both Koreas have used loudspeaker broadcasts in past confrontations, and any restart would be read in Seoul as a deliberate escalation rather than a routine signal.

For now, the message from Seoul is one of deterrence: the border will be defended, and further breaches will draw a firm response, even as officials stop short of spelling out what form that response would take.

Sources: Reuters; Reuters via 101 WIXX.