A North Korean merchant vessel briefly crossed the Northern Limit Line (NLL), the de facto maritime boundary between the two Koreas, in the Yellow Sea on Friday, prompting a swift response from South Korean forces.

According to the Joint Chiefs of Staff (JCS), the 140-meter-long vessel, named Toksong, departed from a North Korean port and crossed the NLL near Baengnyeong Island at 5:06 a.m., advancing as far as five kilometers south of the line. The ship remained in South Korea’s maritime zone for approximately one hour before retreating following warning measures.

The South Korean military initially issued warning broadcasts to the vessel. When the ship continued its incursion, a South Korean Navy vessel fired around 60 warning shots and shells to compel it to withdraw. The 2,800-ton ROKS Cheonan frigate was operating in the area at the time.

Officials noted that a dozen Chinese vessels were nearby, suggesting that the North Korean ship may have crossed the NLL to avoid them. The Toksong reportedly attempted to conceal its identity by displaying a Chinese flag and changing its nationality in its automatic identification system.

“No unusual military activity from North Korea has been detected in relation to this incident,” a JCS official said, emphasizing that South Korea would maintain a firm readiness posture to safeguard the NLL.

This marks the first North Korean intrusion across the NLL in three years. A similar incident occurred in October 2022, when a North Korean merchant ship crossed the line for 40 minutes and advanced 3.3 kilometers into South Korean waters before retreating following warning shots.

North Korea does not recognize the NLL as a legitimate maritime border and has previously claimed the line should be drawn farther south. Shortly after the 2022 incursion, Pyongyang accused the South Korean Navy of violating what it considered its maritime boundary.

The Friday incident underscores persistent tensions in the Yellow Sea and the fragile nature of the inter-Korean maritime boundary. (ILKHA)