Battle of Yeosu The Battle of Yeosu , in December 1998 , was a naval skirmish that began when the Republic of Korea Navy intercepted a North Korean semi - submersible vessel attempting to land commando s on the southern South Korean coast . Background . Throughout 1998 there had been several incidents involving North Korean infiltrators attempting to land on along the South Korean coastline . In the June 1998 Sokcho submarine incident a North Korean submarine was found in South Korean waters off Sokcho entangled in fishing nets , the submarine was towed to a ROK Navy base and when opened the crew were all dead in an apparent murder - suicide . Another infiltration occurred in July when a dead commando and abandoned infiltration craft was discovered near the city of Donghae . Battle . On December 17 , a ten ton North Korean I - SILC class semi - submersible infiltration vessel was observed by a South Korean guard post about 2 km off the coast of Yeosu and ROK Navy ships were scrambled to intercept it . After several warnings were given , the ROK Navy fired warning shots at the semi - submersible . The North Korean craft ignored the warnings and opened fire on the South Korean vessels . It then attempted to escape , fleeing southwest while being tracked by patrol planes and boats , but several hours later it had sunk in of water approximately 100 km south of Geojedo . Aftermath . The ROK Navy attempted to recover the bodies of the dead North Koreans and pieces of the infiltration craft . The body of one North Korean frogman was found . From the size and type of the vessel it was assumed that the entire crew consisted of four sailors and that all had perished . Searches were also conducted on nearby land to make sure that infiltrators had not landed on the coastline . When questioned , the North Korean government denied sending the vessel or knowing anything about its origins . This incident helped fuel increasing tensions between the two governments and an even larger naval skirmish was fought the next year . The ( North ) Korean Central News Agency said on 19 December : The South Korean puppets said that they located a " submarine " in the sea off Ryosu , South Jolla Province , at 11 : 15 p . m . on December 17 and had a battle in which the " submarine " was sunken and they brought a dead body clad in diving - suit to the land . They also said that they issued an order called " Jindogae nN . 1 " throughout the coastal areas of South Korea and have been put on the red alert . This time , too , the puppets described the " incident " as the " intrusion by the north , " shifting the blame on to the north . This frantic anti - communist campaign is a continuation of the anti - communist , anti - north campaign such as the fiction of the " intrusion of the north ' s vessel " near the coast of the Kanghwa island on the West Sea of Korea and the description of a flock of birds as " something mysterious " in the sea off the Kanghwa island . The incidents have nothing to do with the north . Now the South Korean are trying hard to find a pretext for unleashing a war against the north in line with the U . S . imperialists ' moves for war against the DPRK . It goes without saying that the " north ' s submarine infiltration incident " is a farce cooked up for that purpose . We can no longer remain a passive onlooker to the South Korean continuous anti - communist campaign and slander against the north . The campaign can convince no one . We will take resolute measures so that the provokers may drink a bitter cup . We seriously warn the South Korean not to act rashly .