North Korea has been digging special tunnels at a nuclear test site in Punggye-ri in the northern Hamgyong province, sparking concerns that it may be preparing for new nuclear tests, South Korea's news agency Yonhap reported on Sunday, citing government and military sources.
The reclusive communist state conducted its two previous plutonium-fueled nuclear tests, one in 2006 and the other in 2009, at the site, the agency said.
"South Korea and U.S. intelligence authorities have spotted the North building a couple of additional tunnels in Punggye-ri," the agency cited a government source. "It's obvious that North Korea is preparing for a third nuclear test."
The source gave no further details on how many tunnels Pyongyang has built.
"Underground bases can't be reused after a nuclear test blast," the source told the agency, adding that Pyongyang was building more than one tunnel so that it could choose the best one for the nuclear test.
North Korea has been subjected to several rounds of UN Security Council sanctions since it declared itself a nuclear power in 2005. The state broke off talks with South Korea, China, the United States, Japan and Russia on its nuclear program in April 2009, after the United Nations Security Council passed a resolution condemning its missile tests.
In late November that year, Pyongyang disclosed to visiting U.S. experts an operational uranium enrichment facility at Yongbyon, prompting fears that the secretive state had again begun developing nuclear weapons.
MOSCOW, February 20 (RIA Novosti)