See video: North, South Korea trade shelling
North and South Korea exchanged artillery fire along their disputed frontier, raising tensions between the rivals to their highest level in more than a decade. The communist nation warned of more military strikes if the South encroaches on the maritime border by "even 0.001 millimeter."
The skirmish began Tuesday when North Korea warned the South to halt military drills near their sea border, according to South Korean officials. When Seoul refused and began firing artillery into disputed waters - but away from the North Korean shore - the North retaliated by shelling the small island of Yeonpyeong, which houses South Korean military installations and a small civilian population.