Seoul: North Korea blamed South Korea for starting an exchange of artillery on 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 carried by state media.
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 Tuesday 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.