SEOUL, South Korea - North and South Korea exchanged artillery fire along their disputed western sea border on Wednesday, two days after the North designated no-sail zones in the area, the military and news reports said.
North Korea fired several rounds of land-based artillery off its coast, an officer at the Joint Chiefs of Staff in Seoul said. The officer, who spoke on condition of anonymity because of department policy, said no causalities or damage were immediately reported.
South Korea, in response, immediately fired warning shots from a marine base on an island near the sea border, according to Seoul's Yonhap news agency.
Yonhap, citing an unidentified military official, said both Koreas fired into the air.
South Korea's YTN television network carried a similar report on the exchange of fire.
The officer at the Joint Chiefs of Staff said he could not immediately confirm that South Korea returned fire.
The western sea border is a constant source of tension between the two Koreas. Their navies fought a brief gunbattle in November that left one North Korean sailor dead and three others wounded.
The exchange of fire came following a series of mixed signals from North Korea to the South.
Pyongyang offered talks on restarting stalled joint-tour programs and on a joint industrial complex in the North earlier this month. But the communist country also has escalated its rhetoric, with leader Kim Jong Il's all-powerful National Defence Commission threatening to attack the South and break off all dialogue over a reported South Korean contingency plan to handle turmoil in the North.
South Korean Defence Minister Kim Tae-young said last week that his military should launch a pre-emptive strike on North Korea if there was a clear indication that the country was preparing a nuclear attack. The North responded by threatening a war.
In a possible indication that North Korea may be preparing to conduct missile tests or other military exercises in the area, Pyongyang designated two no-sail zones along the sea border through March 29, including some South Korean-held waters, according to the Defence Ministry.
Another Joint Chief of Staff officer said the North's artillery fire landed in North Korean waters. He also spoke on condition of anonymity citing department policy.
The disputed sea border was drawn by the U.N. Command at the end of the Korean War and North Korea has repeatedly insisted it should be moved further south. The dispute also led to bloody naval skirmishes in 1999 and 2002.
The two Koreas are still technically at war because the 1950-53 war ended with an armistice, not a formal peace treaty.