SEOUL, South Korea --- A flaming North Korean patrol ship retreated Tuesday after a brief battle with a South Korean naval vessel inside disputed waters along both countries' western coast, South Korean officials reported.
It marked the first naval clash between the two Koreas in seven years. The timing comes only one week before President Barack Obama plans to visit Seoul, and could have been a strategic move by the North Koreans.
Marking the 22nd time North Korea has violated territorial lines in 2009, according to the South Korean military, the skirmish also serves as a reminder that South Korea and North Korea technically remain at war.
The two Koreas have yet to agree on their sea border 56 years after the 1950-53 Korean War, which ended in an armistice -- not a peace treaty. Instead, they rely on a line that U.N. forces, which fought for the South, drew unilaterally at the end of the conflict.
Hundreds of thousands of combat-ready troops on both sides -- including 28,500 American soldiers -- face each other across the 155-mile-long land border. The area is still "strewn with land mines and tank traps and laced with barbed wire," according to the Associated Press.