North Korean warships are busy plying both East and West Seas, including semi-submersible craft recently moved to a forward base near the Northern Limit Line in the West Sea.

The semi-submersibles are often seen docking at a forward base in waters near the Northern Limit Line in the West Sea, a government source in Seoul said. South Korea and the U.S. are keeping close track of their movements.

The semi-submersibles are normally deployed at a submarine base dozens of kilometers from the NLL. They are about 10 m long and used to carry commandos into enemy territory and can run above the surface of the water at a speed of 70 km/h but submerge 10 to 20 m if necessary. They can slip under the radar even if they run above the water and are equipped with light torpedoes.

In what looks to be a campaign of deliberate coat-trailing in the wake of collapsed inter-Korean talks, an increasing numbe r of North Korean merchant ships, fishery patrol boats and trawlers boats have been running across the NLL into South Korean waters.

A military source said, "We can't rule out that the North will launch a military provocation to create tension while shifting the blame for the scuttled inter-Korean talks" to the South.

