North Korea has defied international warnings and carried out its first testing of a nuclear weapon.

The nuclear test was said to have been carried out underground, and reports from North Korea are touting it as a "success" in that no radiation was leaked, according to the state news (KCNA).

|PIC1|Huge controversy has surrounded the matter since North Korea announced its plans last week, and the international condemnation has been overwhelming.

On Sunday, China and Japan issued a joint statement explaining that it would not tolerate the testing of nuclear weapons by North Korea.

Following the reports that the tests have now taken place, South Korean armed forces have been moved their state of alert, and President Roh Moo-hyun has called an urgent emergency meeting of his government's National Security Council.

Despite the North Korean reports, there seems not to have been any official confirmation of the test, but South Korea's Yonhap news agency is reporting that it took place in Gilju in Hamgyong province at 1036 (0236 BST).

One South Korean official has reported that a 3.5 magnitude seismic tremor had been recorded in the north Hamgyong province, in the north-east of North Korea, according to the BBC.

KCNA, in announcing that the test had taken place described it as an "historic event that brought happiness to our military and people".

|PIC2|"The nuclear test will contribute to maintaining peace and stability in the Korean peninsula and surrounding region."

Japan has stated that if the test was confirmed it would pose a "grave threat" to the region. Japan's Prime Minister Shinzo Abe has just arrived in Seoul for a meeting with Mr Roh, following talks on the crisis with his Chinese counterparts in Beijing.

Abe reported that Japan wanted to co-ordinate its response with the South Koreans, and it is believed that the two nations are also working closely with the US and China.

In Tokyo, ministers were called to an urgent meeting, and the government has now set up a special task force to tackle the issue.

The US not yet issued an official response, but US negotiator Christopher Hill said last week that North Korea had the choice either to have a future or to have nuclear weapons, "but it cannot have them both".

North North's ability to accurately deliver a warhead toward its neighbouring nations is still in doubt though. But the communist nation is no stranger to shocking the international community. In 1998 it fired a long-range ballistic missile over Japan into the Pacific Ocean.

In addition, in July it test-launched seven missiles believed capable of reaching American shores, however they exploded shortly after being fired.