North Korea conducted GPS jamming attacks for the second straight day, the South Korean military said in a statement Saturday, with the move affecting ships and civilian aircraft.
South Korea's Joint Chiefs of Staff said that the attacks, which were also staged Friday, were conducted in North Korea's Haeju and Kaesong areas, and impacted "several" ships and "dozens" of airplanes.
Seoul has warned civilian vessels and aircraft operating in the Yellow Sea to be on alert.
Pyongyang has a history of jamming GPS signals, including multiple attacks in late May and early June of this year from along its northwestern border areas.
Militaries and other nonstate actors can broadcast signals that trick GPS systems — a network of satellites and receivers used for navigation — into thinking planes are somewhere they are not.
Such interference, known as "spoofing," could lead pilots and ship navigators to drift off course, increasing the risk of straying into North Korean airspace or claimed waters, experts say.
North Korea said in July last year that it would shoot down any flights deemed to be U.S. spy planes entering its airspace, while ships straying into waters claimed by Pyongyang could also be subject to attack.
The moves have triggered fears among some observers that an inadvertent shootdown or firing on ships could spiral into conflict.
Most airlines generally avoid North Korean airspace, and the U.S. Federal Aviation Administration bans overflights, citing Pyongyang's tendency to conduct unannounced ballistic missile launches, as well as the potential for electronic warfare. In September last year, the FAA renewed this ban for five years through 2028.
With your current subscription plan you can comment on stories. However, before writing your first comment, please create a display name in the Profile section of your subscriber account page.