"The GPS signal jamming took place in some areas today ... They took place in the western border islands, involving weak signals in the early hours," JCS spokesperson Lee Sung-jun was quoted as saying by Yonhap news agency.
The North has been reportedly conducting "GPS jamming attacks" against the South since Friday, in what is believed to be part of the North's ongoing anti-drone drills.
Jamming attacks were reported last week in the Hezhu and Kaesong regions in the north of South Korea. The South Korean military called on Pyongyang to "immediately stop" the attacks and warned it about repercussions.
North Korea last tried to jam GPS signals in the South Korean waters of the Yellow Sea for several days from late May to early June.