North Korea jammed GPS signals near the inter-Korean border last week in an attempt to disrupt the operations of South Korean ships and aircraft, according to the ROK military, with Seoul reporting over 300 GPS disruptions so far this month.

The ROK military said it detected the jamming signals from the North Korean border cities of Haeju and Kaesong on Friday and Saturday, impacting navigation systems of several vessels and dozens of civilian planes.

“We urge all vessels and aircraft operating in the West Sea (Yellow Sea) to be cautious of North Korean GPS jamming and remain alert,” JCS said