Seoul: North Korean leader Kim Jong-Un ordered his frontline troops onto a war footing from Friday, as military tensions with South Korea soared following a rare exchange of artillery shells across their heavily fortified border.
South Korean forces are already on maximum alert after the North`s military issued an ultimatum on Thursday for Seoul to switch off loudspeakers blasting propaganda over the border within 48 hours or face concerted military action.
An emergency meeting late Thursday of the North`s powerful Central Military Commission (CMC) -- chaired by Kim Jong-Un -- endorsed the ultimatum and ratified plans for "a retaliatory strike and counterattack on the whole length of the front".
According to the official KCNA news agency, Kim ordered frontline, combined units of the Korean People`s Army (KPA) to "enter a wartime state" from Friday 5:00 pm (0800 GMT).
The troops should be "fully battle ready to launch surprise operations" while the entire frontline should be placed in a "semi-war state", KCNA quoted him as saying.
The South Korean Joint Chiefs of Staff responded with a direct message to the KPA, urging it to refrain from any "reckless acts" and warning that it would react strongly to any further provocation.
North Korea has made similar announcements at times of high tension in the past, most recently in 2013 when Kim declared "a state of war" with the South.
Technically, the two Koreas have been at war for the past 65 years, as the 1950-53 Korean War ended with a ceasefire that was never ratified by a formal peace treaty."We`ve been here before several times, but that doesn`t mean it isn`t still dangerous," said Yoo Ho-Yeol, a professor of North Korean studies at Korea University in Seoul.
"There`s a real possibility of this confrontation leading to some sort of armed clash," Yoo said.
South Korea`s defence ministry rejected the North`s ultimatum, which expires at 5:00 pm on Saturday, with a spokesman insisting it would "continue operating the loudspeakers".
Seoul says Thursday`s artillery exchange was triggered by North Korea firing several shells in the rough direction of one of its border propaganda units.
The South responded by firing "dozens" of 155mm howitzer rounds.
Nearly all the shells from both sides landed in their respective halves of the demilitarized zone (DMZ), a four kilometre-wide buffer zone that straddles the actual frontier line.
Direct exchanges of fire across the inter-Korean land border are extremely rare -- mainly, analysts say, because both sides recognise the risk for a sudden and potentially disastrous escalation.
Tensions were already on high-simmer before the shelling, following mine blasts that maimed two members of a South Korean border patrol earlier this month and the launch Monday of a major South Korea-US military exercise that infuriated Pyongyang.
Seoul said the mines were placed by North Korea and responded by resuming the high-decibel propaganda broadcasts after more than a decade.The North has denied any role in the landmine incident, and the CMC meeting in Pyongyang insisted that the situation would only de-escalate if South Korea switched off the loudspeakers.
According to the KCNA report, military commanders were despatched to the frontline to prepare "to destroy the means for psychological warfare... and put down possible counter-actions."
Meanwhile, the Unification Ministry in Seoul, which oversees cross-border affairs, announced Friday that it was restricting access to the North-South`s joint industrial zone at Kaesong.
Only South Koreans with direct business interests in Kaesong -- which lies 10 kilometres (six miles) inside North Korea -- would be allowed to travel there, a ministry spokesman said.
The Kaesong industrial estate hosts about 120 South Korean firms employing some 53,000 North Korean workers and is a vital source of hard currency for the cash-strapped North.
Restricting access will likely be seen as a thinly veiled threat by Seoul to shut the complex down completely if the situation at the border escalates further.
The United States and United Nations both said they were following the situation on the Korean peninsula with deep concern.
The US State Department urged Pyongyang to avoid provoking any further escalation and said it remained "steadfast" in its commitment to defending ally South Korea.