One body found

SEOUL, South Korea (CNN) -- A South Korean Defense Ministry spokesman confirmed that an exchange of gunfire took place when South Korean soldiers discovered a North Korean submarine off the coast at 11:15 p.m. Thursday (9:15 a.m. EST).

South Korean naval forces challenged the Northern submarine with warning shots approximately 2 kilometers off the southern port of Yosu.

According to the Defense Ministry in Seoul, the North Korean vessel ignored all warnings and tried to evade pursuit.

South Korean vessels continued to fire on the submarine, eventually sinking the 10-ton vessel early Friday approximately 100 kilometers off the South's Koje Island.

The body of one of the sub's crewmen was recovered in a wet suit, the ministry said.

"We have found one armed body of a North Korean agent near where the vessel had sunk," Col. Hwang Dong- kyu, spokesman for the Joint Chiefs of Staff told a news conference.

He said seven South Korean patrol vessels were looking for other bodies and wreckage in the area, which has been placed under high alert.

The Defense Ministry said the submersible vessel is capable of carrying a crew of five to six.

Twelve South Korean navy ships and three naval fighter jets were involved in the pursuit, the Defense Ministry said.

North Korea routinely uses submarines to drop off or pick up spies along South Korea's long coastline, officials say. Several have been detected in recent years.

The navy in late November chased a suspected North Korean spy ship across the water demarcation line. In July, the body of a North Korean agent was found washed up on a South Korean beach three weeks after a Northern submarine was captured with nine dead North Koreans inside.

The Associated Press and Reuters contributed to this report.