SEOUL • South Korea's military yesterday threatened retaliation against North Korea after accusing the North of planting landmines inside the Demilitarised Zone border that wounded two soldiers last week, in what it called a cowardly act of provocation.

The latest development came as South Korean President Park Geun Hye yesterday criticised the North's "regrettable" decision to turn back its clocks to a new time zone, saying it would deepen divisions between the two rivals.

In response to the alleged landmine attack by the North, Seoul yesterday ordered the resumption of border propaganda operations against North Korea for the first time in 11 years.

There was evidence to conclude that soldiers from the North crossed the Military Demarcation Line recently to plant the mines, and Pyongyang would be made to "pay a severe price", the South's military told a news briefing.

"We strongly condemn this cowardly act, which would be unthinkable for a normal military," Major-General Ku Hong Mo of South Korea's Joint Chiefs of Staff said, calling it a violation of the armistice agreement that ended the 1950 to 1953 Korean War.

The military declined to comment on what was meant by "severe price" or speculate on the retaliatory options being considered. Analysts said the type of incident made a proportionate response difficult to gauge.

"Realistically, it's hard to see what South Korea can actually do," said Mr Daniel Pinkston, Korea expert at the International Crisis Group in Seoul.

"It's an unacceptable breach of the armistice terms, but you don't want to escalate the situation so it spins out of control. It's very difficult," he added. Yet, the denunciation is likely to provoke an angry response from the North and further raise tensions on the Korean peninsula. The United Nations Command, headed by the United States military and which oversees the armistice, also condemned what it called the North's violation of the truce. It said it would call for a meeting with North Korea's military.

North Korea announced last Friday that it was changing its standard time to GMT+8.30, 30 minutes behind South Korea.

"It is highly regrettable that the North unilaterally changed its time zone with no consultation with us," President Park said yesterday.

REUTERS, AGENCE FRANCE-PRESSE