SEOUL • South Korea has ramped up border security as military tensions flared following landmine blasts for which the presidential Blue House in Seoul has demanded a formal apology from Pyongyang.
South Korea says soldiers from the North sneaked across the border and laid the mines. Three of them were tripped by members of a South Korean border patrol last Tuesday. One soldier had to undergo a double leg amputation, while another lost a leg.
Seoul responded by resuming border propaganda operations after a break of more than a decade, switching on batteries of powerful loudspeakers to blare out messages denouncing border provocations.
Pyongyang is highly sensitive to such campaigns.
The last time the South threatened to turn the speakers back on - in 2010 - the North had vowed to shell the units involved.
"We are strengthening defence postures (along the border) against another potential provocation by the North," South Korea's defence ministry spokesman Kim Min Seok said yesterday.
The army will "respond immediately" if the North opens fire at the loudspeakers, he said, adding that residents in the border area had been advised to exercise caution and farmers to leave their fields.
Until now, there has been no unusual North Korean activity observed along the border.
"For the North, this is a low-cost provocation that creates a big psychological impact on the South," said Mr Kim Yong Hyun, a North Korea expert at Dongguk University in Seoul. "Those North Korean wooden box land mines usually blow away legs only, not always killing their victims."
Mr Kim said the incident was unlikely to lead to an armed skirmish on the tense border but that it would probably harden the South's stance and hamper any short-term efforts to improve ties. The North has not responded to the South's accusation. If the mines were indeed planted by the North, it would be one of its most daring provocations since it shelled a South Korean island in 2010, killing four.
The mine blasts came with cross- border tensions already high ahead of the launch next week of a major South Korea-US joint military exercise condemned by Pyongyang.
The South's Blue House has demanded an apology for what it called a "clear breach" of the armistice agreement that ended fighting in the 1950-53 Korean War.
"We sternly urge North Korea to apologise for this provocation and punish those responsible," Blue House spokesman Min Kyung Wook said. Because the 1953 armistice was never replaced with a peace treaty, the two Koreas remain technically at war.
The defence ministry declined to say how many units were involved in the propaganda broadcasts, which resumed late on Monday.
Media reports suggested loudspeakers had been switched on at up to 11 locations along the border. The defence ministry's Mr Kim said the military was considering other retaliatory moves, but declined to elaborate. According to an official, the messages ranged from snippets of world news and the weather forecast to the superiority of democracy. Sounds from the speakers could be heard 10km to 20km away depending on the time of day.
Both Koreas stopped the high-decibel propaganda exchanges in 2004 during a period of rapprochement. But civil activists from the South have continued - to Pyongyang's fury - to send anti-North leaflets over the border using helium balloons.
AGENCE FRANCE-PRESSE, NEW YORK TIMES