A global agency on banning nuclear tests said Monday that it has picked up evidence of an unusual seismic event in North Korea which is apparently attributable to the detonation of a nuclear bomb.

"The event shows clear explosion-like characteristics and its location is roughly congruent with the 2006 and 2009 DPRK (North Korea) nuclear tests," CTBTO Executive Secretary Tibor Toth said in a statement.

CTBTO is the short for the Comprehensive Nuclear-Test-Ban Treaty Organization to be established to implement a global convention that outlaws nuclear tests.

Toth is now leading the preparatory commission for CTBTO headquartered in Vienna, Austria.

"For now, further data and analysis are necessary to establish what kind of event this is," he said.

If confirmed as a nuclear test, he added, this act would constitute a clear threat to international peace and security, and challenges efforts made to strengthen global nuclear disarmament and non-proliferation, in particular by ending nuclear testing. (Yonhap News)