(Yonhap) – South Korea's ICT ministry said Saturday that North Korea has sent signals to jam Global

Positioning Systems (GPS) in South Korea for the third consecutive day despite Seoul's warning, but no serious damage has been reported.

The government strongly warned North Korea on Friday to immediately end its GSP-disrupting provocations as such actions defy international norms.

The ministry said that the North's GPS-jamming activity has continued since Thursday though there has been no reported serious damage on civilians, such as in the operation of airplanes and ships.

"The disrupting signals have continued to come (from North Korea) though they cycle through influx and diminishing," said an official at the Ministry of Science, ICT and Future Planning.

"There is no noticeable change in the wave pattern."

The ministry said Friday that the North's GPS-disrupting move had affected some 150 planes and 68 ships in South Korea although there has been no significant damage.

Passenger ships and fishing vessels are operating normally in waters off the country's east and west coasts, according to the Coast Guard.

"There was no reported GPS-related damage on Saturday," said a Coast Guard official. "We are closely monitoring the situation and beefing up surveillance for safe sailing."

Seoul's defense ministry said that the North's actions are aimed at raising tension on the divided peninsula amid mounting international pressure on the North to give up its nuclear weapons programs.

The government said the North's disruptive signals are presumed to be able to reach some 100 kilometers from its transmission points near the heavily fortified inter-Korean border, and could possibly affect Seoul.

The ministry said that there has been no reported negative impact on the South Korean military due to the North's GPS-jamming provocation. It warned that it will make North Korea pay a "due" price if Pyongyang does not suspend its provocation.