A train station in China that is so far underground ... In North Korea, the Pyongyang Metro is one of the deepest metro systems in the world, sitting at 100 metres (328 feet) underground.
Last week's accidental shelling of a South Korean village occurred less than 20 miles from the border of the nuclear-armed North.
North Korean foreign ministry calls drills a "dangerous provocative act", claims they will "harm US security".
TASS/. North Korea’s Supreme Leader Kim Jong Un left Pyongyang on a special train in the late afternoon on September 10 for a visit to Russia, the Voice of Korea radio station reported.
North Korea carried out a test-launch of its strategic cruise missiles in the Yellow Sea this week, Pyongyang's state media ...
Such drills infurate Pyongyang, which regards them as rehearsals for invasion and routinely responds with weapons tests of its own.