Seoul: South Korea on Monday ordered border propaganda operations against North Korea to resume for the first time in 11 years, in retaliation for landmine blasts that maimed two of its soldiers during a frontier patrol.
The Defence Ministry said banks of loudspeakers positioned at various spots along the border would be switched on for the first time since 2004 and used to blast out messages denouncing North Korean provocations.
The move will infuriate North Korea and likely trigger a surge in cross-border tensions at a time of already severely strained relations between Seoul and Pyongyang.
The order came hours after Seoul vowed Pyongyang would pay a "harsh price" for allegedly planting the landmines that detonated last Tuesday in the South Korean half of the Demilitarized Zone (DMZ) -- a buffer area flanking both sides of the inter-Korean frontier.
One soldier injured in the blasts underwent a double leg amputation, while another had one leg removed.
The US-led United Nations Command which oversees the armistice that ended the 1950-53 Korean War, said analysis of the mine debris showed them to be North Korean "wooden box" landmines placed on a known South Korean patrol path.
"The investigation determined that the devices were recently emplaced," it said, ruling out the possibility they were old mines displaced over the border by shifting soil patterns.
The South`s Joint Chiefs of Staff vowed that North Korea, which has yet to react to the charge that it was behind the blasts, would "pay a harsh price proportionate for the provocation it made".
Describing the attack as a "baseless act" and "wanton violation" of non-aggression accords, it urged the North to apologise and punish those responsible.A Defence Ministry official described the resumption of border propaganda operations as only a "first step."
The loudspeakers had blared out messages extolling the virtues of South Korea for years before the practise was discontinued by mutual agreement in 2004 during a period of rapprochement between the two Koreas.
Seoul had threatened to resume the campaign in 2010 after the sinking of a naval corvette that was blamed on a North Korean submarine.
But although the loudspeakers were re-installed, they were never put back into use as Seoul limited itself to a number of direct FM radio broadcasts into North Korea instead.
Switching the loudspeakers back on is sure to trigger a strong reaction from the North, which already complains regularly and bitterly about Seoul`s refusal to ban activists floating anti-North leaflets across the border by helium balloon.
Because the 1953 armistice was never replaced with a peace treaty, the two Koreas remain technically at war and the DMZ -- despite its name -- is one of the most heavily-militarised frontiers on the planet.
Yang Moo-Jin, a professor at the University of North Korean Studies in Seoul, said North Korea was almost certain to deny planting the mines, and added that it was difficult to deduce any motive for such an operation.
"Whatever the reason, South Korea has limited options to respond, especially inside the DMZ where military activity is so closely controlled and monitored," Yang said.
Some analysts suggested it was a pre-emptive attempt to raise tensions before a major South Korea-US military exercise scheduled to begin next week.
On Saturday North Korea had promised a "tough military counter-action" if the joint drill went ahead.
The last direct attack on the South was in November 2010 when North Korea shelled the South Korean border island of Yeonpyeong, killing two civilians and two soldiers.
South Korea responded by shelling North Korean positions, triggering brief fears of a full-scale conflict.
The latest incident comes at a sensitive time, with both Koreas preparing to commemorate the 70th anniversary on Saturday of the 1945 liberation of the Korean peninsula from Japanese rule.
There had been hopes that the anniversary might be an opportunity for some sort of rapprochement, but efforts to organise a joint commemoration went nowhere. Pyongyang refused to consider talks because of Seoul`s refusal to cancel its military drills with the United States.