South Korea says electronic jamming signals from the communist North have disrupted hundreds of civilian flights, but says no aircraft is in danger.
Seoul has issue a warning notice for pilots and airlines, and pilots are now using other navigation devices.
About 250 flights operated by South Korean and foreign airlines have been affected by the GPS jamming from North Korea since last weekend.
"We've confirmed the GPS jamming signals have been stemming from the North," said Lee Kyung-Woo, a deputy director at the state Korea Communications Commission.
It is not the first time North Korea has been blamed for jamming GPS systems, with Pyongyang accused of disrupting South Korean military communications last year.
A spokesman for Seoul's joint chiefs of staff declined to say whether the jamming was also directed against the military.
"There has been no problem in our military operations," he said.
Minister Kim Tae-Young told parliament the North had imported Russian equipment to jam GPS reception and could achieve this effect over a distance of up to 100 kilometres.
Mr Kim said the North was thought to have been responsible for the intermittent failure of GPS receivers on naval and civilian craft along the west coast from August 23 to 25 that year.
