Two Koreas exchange warning shots along Northern Limit Line

The image, provided by Yonhap News TV, depicts the Northern Limit Line (NLL) in the Yellow Sea, a de facto maritime border. [YONHAP]

South Korea's military said Monday it has fired warning shots at a North Korean ship that crossed the Northern Limit Line (NLL) in the Yellow Sea, the de facto maritime border. The North also opened "warning fire" against the South in response.

A North Korean merchant vessel violated the NLL in waters near the front-line island of Baengnyeong at 3:42 a.m. and it retreated northwards after the South's Navy issued warning messages and fired warning shots, according to the South's Joint Chiefs of Staff (JCS).

Shortly after the announcement, the North Korean military claimed a South Korean warship violated the western sea boundary and it fired 10 artillery shells into the western sea from multiple rocket launchers in its "threatening and warning fires."

The South Korean escort ship invaded the Military Demarcation Line controlled by the North's military by 2.5-5 kilometers (1.5-3 miles) at 3:50 a.m. on the excuse of carrying out crackdowns on an unidentified vessel, an unnamed spokesman for the General Staff of the Korean People's Army (KPA) said in a statement.

"The KPA General Staff once again sends a grave warning to the enemies who made even naval intrusion in the wake of such provocations as the recent artillery firing and loudspeaker broadcasting on the ground front," read the English-language statement carried by the North's Korean Central News Agency.

The South's JCS also said it detected the North's launch of 10 artillery shells, which started at around 5:14 a.m., in violation of the Sept. 19 Comprehensive Military Agreement between the two sides aimed at reducing border tensions. The JCS called it a provocation harming peace and stability not only on the peninsula but also in the international community.

The exchange of warning fire between the two Koreas came amid heightened tensions on the peninsula amid North Korea's continued provocations, including a barrage of ballistic missile tests and firing of artillery shots.

Speculation is rampant that North Korea may conduct a nuclear test soon, as China's key party congress ended on the weekend.

The North's ships have frequently intruded past the NLL, as it has long demanded that the line be moved farther south.

Drawn by the U.S.-led United Nations Command at the end of the 1950-53 Korean War, the NLL acts as the de facto sea border between the two Koreas. Pyongyang does not recognize the border, and the two sides fought bloody battles there in 1999, 2002 and 2009.

Yonhap