North Korea has taken control of Mt. Kumgang, a jointly maintained tourist area in which South Korea's Hyundai Asan had invested more than $1.5 billion for a hotel, hot springs, shopping mall, and a road inside the North.
North Korea has threatened more punishment for an American prisoner who illegally entered the country.
Analysts and diplomats are scratching their heads as to why North Korea continued firing artillery shells into its disputed maritime border with the South for the second day in a row.
Pyongyang may fulfill a vow to conduct another nuclear test, analysts say. It may also be testing US response.
South Korean fighter pilots are 'ready to scramble' as North Korea prepares a missile launch.