Seoul: South Korea on Tuesday warned that it will unleash "enormous retaliation" if North Korea launches fresh attacks against its territory.
A visibly angry South Korean President Lee Myung-bak said that the North`s "indiscriminate attack on civilians can never be tolerated."
"Enormous retaliation should be made, to the extent that [North Korea] cannot make provocations again," he said minutes after attending an emergency security meeting shortly after the artillery bombardment from its neighbour.
His comments were posted on the presidential website and made during a visit to the Joint Chiefs of Staff`s command and control room.
The assault is one of the most serious in the decades since the war, given the involvement of civilians, although previous firefights around the disputed maritime border have resulted in a higher number of casualties.
In a short statement carried by the official KCNA news agency, the North said the South had fired first – presumably in reference to a live-fire drill being carried out as part of annual military exercises. It said it had repeatedly warned the South not to go ahead with the drill.
Analysts said that despite the seriousness of the clash, the situation was unlikely to escalate dramatically given the high stakes involved for all parties.
It comes amid growing international concern over reports that North Korea has a new uranium enrichment facility.
North Korea has blamed South Korea for starting an exchange of artillery Tuesday across their border in the Yellow Sea while threatening "merciless" strikes against its neighbour if it violates that border.
If South Korea intrudes into its territorial waters "even 0.001 millimetres, the revolutionary armed forces of (North Korea) will unhesitatingly continue taking merciless military counter-actions against it," the North`s top military command said in a statement.
South Korea said the North began firing, raining down more than 100 shells near the border, setting forests and houses on Yeonpyeong island ablaze, killing two South Korean soldiers, injuring at least 13 others and wounding at least four civilians.
The island lies 12 km from North Korea`s coast and three kilometres south of the sea border established by the UN after the 1950-53 Korean War. North Korea does not recognise that border and has said it should run south of Yeonpyeong.
Naval battles have taken place in the area in 1999, 2002 and November 2009. A South Korean warship was also sunk near the border in March 2010, killing 46 sailors. Seoul blamed Pyongyang for the sinking, but North Korea denied involvement.
The statement by the North Korean military command said that the only border that exists in the seas west of the two Koreas is the one set by Pyongyang.
South Korea "should bear in mind the solemn warning of the revolutionary armed forces that they do not make empty talk", it said.
(With Agency Inputs)