The history of the Korean People's Army Naval Force is short compared to most modern navies. It began with the creation of a "Maritime Security Force" on June 5, 1946. The headquarters for the force was based in the North Korean city of Wonsan, and was operational by July 1946. The headquarters were then expanded and moved to the capital, Pyongyang, for more effective management of seabound traffic, and the forces were renamed Marine Patrols in December of the same year. The Marine Patrol Academy was established in Wonsan in June 1947 in order to train and commission a professional corps of naval officers. Initially operating under the North Korean Ministry of Interior(내무성), commanding authority was transferred to the National Security Department(민족보위성,precursor to Ministry of defence) on August 20, 1949. The introduction of a torpedo fleet into the unit on August 29, made it formally recognized as a naval force, and the date was commemorated as Navy Day until it was changed to honour the June 5th date in 1993. Korean People's Army Naval Force organization in 1950 Operations and engagements Landing operation near Kangnung and Samcheok (June 25–26, 1950) Battle of Chumonchin Chan (July 2, 1950) Battle of Haeju (September 10, 1950) Pueblo incident (January 23, 1968) Gangneung Infiltration (September 17, 1996 - November 5, 1996) Battle of Yosu (December 17–18, 1998) First Battle of Yeonpyeong (June 9–15, 1999) Battle of Amami-Ōshima (December 22, 2001) Second Battle of Yeonpyeong (June 29, 2002) Battle of Daecheong (November 10, 2009) ROKS Cheonan sinking (March 26, 2010) Landing operation near Kangnung and Samcheok June 25, 1950, North Korean troops invade South Korea. On the morning of 25 June an armed North Korean steamer (ex US transport of 1000t, taken by South Korean communists to the North in October 1949) tried to disembark about 600 troops 18 miles off Pusan, but it was sighted and sunk by Republic of Korea Navy (ROKN) patrol craft Bak Du San ("PC 701"). This was the first naval surface action of the war. At the same time North Korean convoy (2 submarine chasers, 1 minesweeper and 20 schooners) started disembarkation of 4 battalions in Kangnung area; another convoy (2 minesweepers, 1 patrol ship, 1 submarine chaser) - disembarkation of communist guerrillas near Samcheok. ROKN minesweeper YMS-509, patrolling the area near Okgye, tried to prevent disembarkation, but after a short battle, North Korean minesweeper No 31 was forced