SEOUL, South Korea -- More than 250 flights in and out of South Korea have experienced GPS signal jamming since the weekend, with North Korea high on the list of suspects, officials said Wednesday.
Similar jamming in the past was traced to the reclusive North, which last month breached U.S. Security Council resolutions with a failed long-range rocket launch and was blamed for cyber attacks on South Korean financial institutions last year.
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None of the flights, including 11 operated by foreign airlines, was in danger, the Transport Ministry said, with automatic switching of navigation to alternative systems.
"As it happened at the time of (military) drills in 2010 and 2011, we suspect North Korea was engaged in jamming signals," a government official said.
Lee Kyung-woo, of the Korea Communications Commission, told NBC News that backup electronic systems maintained safety and that it and other relevant government agencies would continue to monitor the situation.
A Defense Ministry spokesman told NBC News that he could not confirm or mention what type of measures were to be taken against the North's suspected jamming.
North Korea has stepped up its rhetoric against the South in recent weeks, hurling personal insults at South Korean President Lee Myung-bak and threatening to reduce the capital Seoul to ashes.
The North is expected to conduct a third nuclear test soon, possibly using a uranium device that would infuriate neighboring countries and the United States, which have been involved in talks to try to rein in its nuclear weapons program.
The North's ability to wage cyber war from North Korea is seen by the South, one of the world's most wired countries, as increasingly sophisticated.
News reports said North Korea operates vehicle-mounted jamming devices that can disrupt signals up to 60 miles away and is developing systems with further reach.
The Associated Press and Reuters contributed to this report.
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