North Korea has been trying to disrupt air and ground traffic in the South for the fifth day running, the government said Wednesday. Aircraft taking off or landing in the Seoul metropolitan area and ships traveling off the west coast have been affected by electronic jamming signals from the North since Saturday.
The Ministry of Land, Transport and Maritime Affairs said that the GPS of a total of 272 airplanes had been disrupted as of 3:10 p.m. on Wednesday. They were taking off or landing at Incheon and Gimpo airports and flying over Osan and Taean, chiefly in the central region.
The signals have been disrupted since the North threatened on April 23 to take "special actions" against the South.
But the ministry said this did not disrupt aircraft navigation because they also use other navigation devices like the very-high-frequency omni-directional range (VOR) and inertial navigation system (INS) if their GPS systems are jammed.
The GPS of ships traveling off the west coast have also been disturbed, but they too can locate their positions using other devices such as radar.
Based on triangulation of the jamming waves, the Korea Communications Commission concluded that they came from the Kaesong area, a staffer said. Jamming signals continued intermittently at intervals of several hours.
"This is the third time the North has sent out jamming signals after August 2010 and March 2011," he added. The first and second time, the signals came during the joint military exercises with the U.S., but this time no such drills are underway.