North Korea attempted to disrupt the reception of Global Positioning System signals on the front-line islands of South Korea in the West Sea for three consecutive days from Tuesday, coinciding with annual combined military drills between Seoul and Washington, the South Korean military confirmed on Friday.

South Korea's Joint Chiefs of Staff detected signals sent from North Korea, which were assessed as attempts to interfere with the reception of GPS signals on the Five West Sea Islands multiple times from Tuesday noon to Thursday.

These five border islands include Baengnyeong Island, Daecheong Island, Socheong Island, Yeonpyeong Island and U Island.

The South Korean military noted that the GPS interference started on the second day of the 11-day Freedom Shield computer simulation-based command post exercise between South Korea and the US. Concurrent with FS 24, South Korea and the US are conducting 48 field training exercises in March.

North Korea's disruptions "did not affect military GPS," a military official, who requested anonymity, told The Korea Herald.

However, the official explained that the automatic navigation systems of some vessels near the front-line border islands in the West Sea were affected by GPS interruptions.

The official clarified that North Korea's GPS interruptions did not result in any damage to vessel operations.

Additionally, the official warned that the "military will take retaliatory measures" if GPS disruptions lead to any damage, whether civilian or military.

GPS signals are broadcast by GPS satellites to enable satellite navigation. GPS signals are essential because they provide accurate positioning, navigation and timing information critical for various applications, including transportation, emergency response and military operations.

Since 2010, North Korea has sporadically attempted to interfere with GPS signals, with not all instances receiving media coverage, according to the South Korean military.

A significant incident occurred in April 2016, just before South Korea's legislative election, when North Korea conducted high-power signal interference. The disruption impacted the navigation of ships and airplanes reliant on GPS.

These latest three-day GPS disturbances also occurred around one month before South Korea's legislative election scheduled for April 10.