North Korea conducts third nuclear test, sparks condemnationNorth Korea conducted its third-ever nuclear test on Tuesday, a move likely to anger its main ally China and increase international action against Pyongyang and its new young leader, Kim Jong-un.U.N. Secretary-General Ban Ki-moon condemned North Korea's test, saying it was a "clear and grave violation" of U.N. Security Council resolutions.South Korea said the size of the seismic activity indicated a nuclear explosion slightly larger than the North's two previous tests at 6-7 kilotons, although that is still relatively small. The Hiroshima bomb was around 20 kilotons.The U.S. Geological Survey said that a seismic event measuring 5.1 magnitude had occurred on Tuesday, with North Korea later confirming the nuclear test.