South Korea seized a North Korean fishing boat that crossed over the sea demarcation line that separates the two Koreas in the Yellow Sea, the military said Thursday.

   According to the Joint Chiefs of Staff (JCS), the single boat crossed over the Northern Limit Line (NLL) at 5:26 p.m. and sailed 1.8 km into South Korean-controlled waters. It was seized, along with its three crew, at around 8 p.m. after it failed to heed warnings by a Navy patrol boat that included four verbal orders to retreat and even shots fired across the bow of the trespasser.

   The intrusion took place near Baengnyeong Island, South Korea's northernmost territory in the Yellow Sea that lies off the coast of North Korea's Hwanghae Province.

   "The boat was captured and boarded," the JCS said. It said the move took place after weather conditions deteriorated in the area and there was a need to ensure the safety of the North Korean crew.

Poor visibility likely prevented the boat from finding its bearings, it added.

   "The crew will be questioned by authorities as to why they crossed the NLL," he said.

   He stressed that once the cause of the intrusion is determined, appropriate actions will be taken.

  The JCS then warned that should the North use the seizure as an excuse to provoke the South, its forces will respond in a resolute manner.

   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 has said it does not recognize the line as legitimate, and the area has been the site of several bloody clashes between the to opposing sides. (Yonhap)