North Korea conducts second underground nuclear test

According to the state-run KCNA agency, North Korea staged an underground nuclear test. North Koreans are saying the test carried out Monday was a success.

As Sky News reports, "The North "successfully conducted another underground nuclear test on May 25 as part of its measures aimed at strengthening its self-defence nuclear deterrent in every way," the Korean Central News Agency (KCNA) said." Officials in South Korea said a tremor was been detected around the town of Kilju. The northeastern town is the same location where the first test in October 2006 took place. According to South Korea President Lee Myung-bak, the test calls for an emergency security session. Japan says it will respond to the North Korea's nuclear test "in a very responsible manner" at the United Nations. Update: Seoul's Korea Meteorological Administration detected a 4.5 magnitude artificial earthquake at 9:54 a.m. South Korea's Joint Chiefs of Staff said it postponed this week's three-day workshop of over 400 general-grade officers. The nation put its troops on a heightened alert after the nuclear test of a "new higher level." Yonhap news reports:

The Ministry of National Defense launched a "crisis management" team of senior commanders, headed by a three-star officer, ministry spokesman Lee Bung-woo said. "The team will come up with measures to respond to the test," he said.

Russia's U.N. Ambassador told Reuters the United Nations Security Council will hold an emergency meeting later on Monday over North Korea's nuclear test. As Adjix reports:

The United States is "gravely concerned" after North Korea said it carried out a nuclear test on Monday morning, a U.S. State Department official told BNO News."We are gravely concerned about North Korea's claims, we are analyzing the data," a U.S. State Department official told BNO News. "The U.S. Geological Survey confirmed that a seismic event took place consistent with the test. We are consulting with our six-party and U.N. Security Council partners on the next steps," he added.