SEOUL, South Korea - North Korea said Monday it has performed its first-ever nuclear weapons test. The country's official Korean Central News Agency said the underground test was performed successfully and there was no radioactive leakage from the site.(Full Coverage on North Korea's Nuclear Crisis ) 

File IKONOS satellite image of the Yongbyon nuclear facility, located about 100 kms (62 miles) north of Pyongyang, taken August 13, 2002. North Korea has carried out an underground nuclear test, the North Korea's Central News Agency (KCNA) said on October 9, 2006. [Reuters]

"The nuclear test is a historic event that brought happiness to the our military and people," KCNA said.

"The nuclear test was conducted by 100 percent of our wisdom and technology," the agency said.

"Our science research section has safely and successfully conducted an underground nuclear test on October 9," it said.

It added that there was no leak or danger from the test.

South Korea's presidential Blue House said a tremor had been detected in North Korea on Monday.

It said South Korea's Institute of Geoscience and Mineral Resources had detected a tremor of a magnitude 3.58 to 3.7 at 0135 GMT.

South Korea's Yonhap news agency said the test was conducted at 10:36 a.m. (9:36 p.m. EDT Sunday) in Hwaderi near Kilju city, citing defense officials.

South Korean President Roh Moo-hyun convened an urgent meeting of security advisers over the issue, Yonhap reported.

North Korea said last week it would conduct a nuclear test as part of its deterrent against a possible U.S. invasion.