North and South Korea are still technically at war, and have been for 60 years, because the fighting between 1950 and 1953 conflict ended with a ceasefire, and not a peace treaty. Over the past four decades there have been numerous violent episodes, including: January 1968 - Thirty-one heavily armed North Korean spies infiltrate deep into Seoul with a mission to assassinate then President Park Chung-hee; 28 were shot to death. October 1983 - Seventeen senior South Korean officials including several cabinet ministers were killed when a bomb went off in the capital of Burma, now Myanmar. A Burmese court ruled that it was a North Korean plot.
November 1987 - A Korean Air flight departing Baghdad and bound for Seoul exploded in mid-air over the Bay of Bengal, killing 115. A North Korean spy was convicted by a South Korean court for planting a bomb. Another North Korean believed to have been involved in the bombing of the plane committed suicide. December 1998 - South Korean navy sinks a submersible North Korean spy vessel on east coast of the peninsula. A scuba diver from the North is found dead. June 1999 - At least 17 and as many as 80 North Korean sailors are killed in naval clashes near the disputed maritime border between the Koreas, the Northern Limit Line (NLL), in the Yellow Sea. One of the North's vessels was sunk, others damaged. The battle followed nine days of incursions by the North into South Korean waters.
June 2002 - In a skirmish between South and North Korean naval vessels in the Yellow Sea, one South Korean frigate is sunk and six South Korean sailors die. As many as 13 North Koreans may have perished. July 2003 - South Korea says its troops returned machine gun fire a minute after the North shot at an observation post in the Demilitarised Zone (DMZ) buffer between the two states. May 2006 - Two North Korean soldiers enter the DMZ and cross into South Korea. They return after South Korean soldiers fire warning shots.
July 2008 - A 53-year-old South Korean woman, out for an early-morning stroll, is shot dead by the North Korean military on a restricted beach near North Korea's Mount Kumgang. The killing led to the current South Korean government suspending tours to North Korea by South Koreans initiated by its predecessors. November 2009 - The two Koreas have a brief naval fight just south of their maritime border that causes damage to vessels on both sides. January 2010 - The two Koreas exchange artillery fire near the maritime border. March 2010 - The South Korean navy corvette Cheonan sinks, killing 46 sailors. An investigation said a North Korean submarine fired a torpedo, breaking the ship in two. Reuters