More than 120 ships, including Coast Guard vessels and a passenger boat, have reported malfunctions in their navigation systems since the apparent jamming of satellite signals by North Korea last week, maritime police said Friday.
According to the Coast Guard in Incheon, west of Seoul, a total of 122 ships were affected by the disruption to Global Positioning System (GPS) signals last Saturday. Among the vessels were eight patrol boats belonging to the Coast Guard, a passenger liner carrying 387 people and a petrol products carrier.
Fishing boats operating near the tense western maritime border with North Korea also reported errors in their navigation systems, although none of them led to accidents, Coast Guard officials said.
"Last Saturday, I was sailing toward Incheon when the GPS stopped working, and I almost sailed north," said a fisherman from the western border island of Yeonpyeong, who gave only his surname Kim.
Koreans are not free to travel between the sides as the 1950-53 Korean War ended in a truce and left them in a technical state of war.
On Wednesday, the transport ministry said about 250 commercial flights in and out of international airports at Incheon and Gimpo, also west of Seoul, were affected by the jamming, although they were not put in danger.
South Korea came under similar electronic attacks in March of last year, and in August and December of 2010, all of which were blamed on the North. South Korean Defense Minister Kim Kwan-jin has said anti-jamming programs are being developed to counter the attacks.
The defense ministry has also said the North operates a regiment-sized electronic warfare unit near its capital Pyongyang, and some battalion-sized units closer to the inter-Korean border.
Cross-border tensions have peaked in recent years, with Seoul blaming Pyongyang for the March 2010 sinking of a warship and the November 2010 shelling of Yeonpyeong Island, the two of which killed a total of 50 South Koreans, mostly soldiers.
Last month, North Korea threatened to launch special military actions to reduce Seoul to ashes in minutes over an alleged insult to the North's dignity. (Yonhap)