SEOUL, May 13 (Yonhap) -- North Korea said Wednesday it will stage firing drills near the tensely guarded western sea border this week, according to the South Korean military.

In a notice to Seoul's Joint Chiefs of Staff, Pyongyang said it will "carry out firing drills between 3 p.m. today and Friday in their territorial waters just above the Northern Limit Line (NLL)," the JCS said.

The NLL is the de facto inter-Korean sea border in the Yellow Sea, though Pyongyang does not acknowledge it and has demanded the line be drawn farther south. After the 1950-53 Korean War ended in a ceasefire, the U.S.-led United Nations Command drew the line.

Earlier this week, the North threatened to launch a strike against South Korean warships "without any prior warning," claiming South Korean naval speedboats intruded into the North's territorial waters in the Yellow Sea two to three times.