3-4 N.Korean subs disappear after leaving east coast bases

South Korea is tracking three to four North Korean submarines that disappeared after recently leaving two bases on the east coast, a South Korean military source said Wednesday.

The source said the submarines are presumed to be of the 370-ton class that the South Korean military has been unable to locate since they departed from two submarine bases on the east coast.

Another source said, “North Korea seems to be actively conducting submarine infiltration drills in the wake of warmer weather recently,” adding, “(The South Korean military) is closely watching the situation without ruling out the possibility of a provocation disguised as a drill.”

Seoul is preparing for a potential surprise attack by Pyongyang aimed at South Korean naval vessels or military bases, as the North has threatened to make strong provocations against the South while planning to launch a long-range rocket between April 12 and 16.

Moreover, the South predicts that the North is highly likely to catch the South off guard at a time when the latter`s military has concentrated its surveillance and strike force in areas near the Northern Limit Line, the de factor maritime border between the two Koreas, after the North sank a South Korean naval vessel in 2010.

Choi Yun-hee, the South Korean Navy`s chief of staff, told The Dong-A Ilbo last month that the North is highly likely to turn the South’s attention to the west coast and commit provocations on the east coast or in rear areas.

The North has 80 percent of its 70 to 80 submarines and submersibles ranging from 130 to 1,500 ton-class deployed on the east coast. It has large submarine bases in South Hamgyong Province.

Military authorities of South Korea and the U.S. monitor movement at the submarine bases. Once they depart from the bases and go under water, however, tracking the vessels down is difficult.

ysh1005@donga.com