Japan responded quickly to the suspected nuclear test carried out by North Korea earlier in the day Friday by convening a national security meeting to discuss countermeasures.

A magnitude 5 earthquake was detected near North Korea's nuclear test site in its northeastern region at around 9:30 a.m., raising suspicions that Pyongyang may have conducted its fifth nuclear test.

If confirmed, this would be the latest nuclear provocation since January when it carried out its fourth nuclear test detonation, which drew strong condemnation from the international community and the toughest resolution ever by the United Nations Security Council in March.

Japanese Foreign Minister Fumio Kishida told reporters that he has set up and is running an emergency team dedicated to monitoring related developments.

He also said that a nuclear test by the North would violate UNSC resolutions and agreements reached through the long-stalled six-party denuclearization talks involving the two Koreas, Japan, the United States, Russia and China.

China, the North's closest ally and the host of the six-party talks, has yet to express its official stance on Pyongyang's suspected nuclear test. (Yonhap)