SEOUL, South Korea -- North Korea fired more artillery near its disputed western sea border with South Korea on Thursday, a day after it lobbed dozens of shells during military exercises that prompted the South to respond with warning shots. North Korea fired several artillery shells early Thursday that are believed to have landed in its waters, an official at Seoul's Joint Chiefs of Staff said. The official, speaking on condition of anonymity citing department policy, said South Korea did not respond but was closely watching the North's maneuvers. The poorly marked sea border ��" drawn by the American-led U.N. Command at the end of the Korean War ��" is a constant source of tension between the two Koreas. Their navies fought a skirmish in November that left one North Korean sailor dead and three others wounded, and engaged in bloodier battles in the area in 1999 and 2002. It was the first exchange of fire between the two Koreas since November's skirmish, and could be aimed at raising tensions to emphasize that the peninsula remains a war zone and push for a treaty formally ending the 1950-53 Korean War.
