North Korea announced Monday that it had carried out what it called a successful nuclear test, defying international pressure to abandon its nuclear program. Shortly thereafter, several missiles were also test-fired. While the explosive power of the nuclear test has not yet been verified, early reports indicate the bomb may have been as powerful those dropped on Hiroshima and Nagasaki, Japan, during World War II. The UN Security Council condemned the tests as a "clear violation" of a 2006 resolution requiring North Korea to abandon its nuclear program.