N. Korean semi-submersibles moved near western sea border: report

North Korea has recently moved semi-submersible boats used for infiltration to a forward base near its sea border with South Korea, prompting the South Korean and U.S. militaries to strengthen surveillance, a Seoul daily reported Monday.

The semi-submersibles, which are normally deployed at a base dozens of kilometers from the de facto sea border, have been seen docking at a forward base near the Northern Limit Line, the de factor sea border, a South Korean government source told The Chosun Ilbo.

The boats, which can run above the surface of the water at a speed of 70 kilometers per hour but submerge 10-20 meters if necessary, are used to carry commandos into enemy territory.

They can slip under the radar even if they run above the water and are equipped with light torpedoes.

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

"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, a South Korean military source was quoted as saying.

The governmental talks between the two Koreas, scheduled for last week, were called off after the two sides failed to resolve the difference over the level of chief delegates.

The two Koreas' navies have clashed in the past near the maritime border in the Yellow Sea.

North Korea does not recognize the NLL, which was unilaterally drawn by U.S.-led U.N. forces at the end of the 1950-1953 Korean War, and insists the sea border line be drawn further south.