UNITED NATIONS, March 17 -- A UN-backed nuke watchdog confirmed that it has not detected an explosion or crash linked to the disappearance of the Malaysian plane, a UN spokesman told reporters here on Monday.

"Regarding the missing Malaysian Airlines flight, the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), based in Vienna, confirmed over the weekend that neither an explosion nor a plane crash on land or on water had been detected so far," said Stephane Dujarric, spokesperson for UN Secretary-General Ban Ki-moon, at the daily briefing.

Flight MH 370, with 239 people on board, vanished early March 8 on its way from Kuala Lumpur to Beijing. The search for the missing aircraft has now been expanded deep into the northern and southern hemispheres.

Adopted by the UN General Assembly on Sept. 10, 1996, the CTBTO is an international organization designed to promote the Comprehensive Nuclear-Test-Ban Treaty, which bans nuclear test explosions. The organization operates a worldwide monitoring system to collect acoustic and seismic signals.

Therefore, airplane accidents, if there is any, may be detected by the CTBTO's International Monitoring System, said Dujarric. " This verification system has been put in place to detect nuclear explosions but is also able to detect the explosion of a larger aircraft, as well as its impact on the ground or on water."

The spokesperson noted that the Executive Secretary of the CTBTO, Lassina Zerbo, had mentioned this possibility, saying that he will put the sensors of the organization at work.

"He also encouraged all scientists from member states to carefully study the available data," Dujarric added.

In the past, CTBTO stations have detected some plane accidents, including the crash of a plane at Narita airport in Japan in March 2009.