MOSCOW, November 10 (RIA Novosti) - The...

"No South Korean casualties were immediately reported," the agency quoted a South Korean defense official as saying.

The official blamed a North Korean patrol vessel saying it crossed the border and prompted South Korea to fire warning shots. He said the North fired back.

In 1999 and 2002 deadly clashes occurred along the disputed demarcation line, unilaterally drawn by the United States in 1953 and not recognized by North Korea.

Nonlethal armed incidents have also occasionally taken place along the border, which is called the Northern Limit Line.