Seoul scrambled military aircraft, including F-35A fighter jets, in response, according to the JCS.

The JCS said the North Korean aircraft were detected flying about 25 kilometers north of the Military Demarcation Line in the central region and about 12 kilometers north of the Northern Limit Line, a de facto inter-Korean border in the Yellow Sea, between 10:30 p.m. Thursday and 0:20 a.m. Friday. They were also spotted near the inter-Korean border in the eastern part of the peninsula, according to the JCS.

The North Korean aircraft were detected south of the Special Reconnaissance Line that triggers a response by Seoul, according to the JCS.

It marks the second time in a week North Korea flew military aircraft near the inter-Korean border.

Pyongyang had a group of 12 fighter jets and bombers fly north of the Special Reconnaissance Line last Thursday. (Yonhap)