Reported Blast in N. Korea Fuels Arms Concerns

Concerns about North Korea’s nuclear arms program were fueled over the weekend by reports of a mysterious explosion in the isolated northern reaches of the country, but officials here could not say immediately whether a cloud spotted by satellite was a weapons test or some other kind of fire.

The unexplained incident took place Sept. 9, an important holiday marking the 56th anniversary of the communist nation’s founding.

“Last week, our seismic sensors detected some sort of explosion in the North. But our analysts don’t think that it was linked to a nuclear test,” a senior South Korean Foreign Ministry official told The Times.

South Korea’s Yonhap news agency quoted an unnamed diplomat in Seoul as saying, “We understand that a mushroom-shaped cloud about 3.5 to 4 kilometers [2.2 to 2.5 miles] in diameter was monitored during the explosion.” The source added, “It doesn’t seem to be an ordinary explosion.”

The blast apparently took place in North Korea’s Yanggang province, about six miles from the Chinese border. An unnamed source in Beijing told Yonhap that the blast formed a crater large enough to be noticed by satellite and that the explosion could have been larger than the one in April that killed 161 people at a railway station in the North Korean town of Ryongchon.

North Korea is believed to have enough weapons-grade plutonium for several nuclear bombs, although the country has not tested an atomic weapon. Tortuous negotiations to coax the regime into ending its nuclear program in return for aid and security guarantees have stalled in recent weeks and the prospects are dimming for a breakthrough before the U.S. election.

North Korea suggested Saturday that it might not participate in further six-party talks over its nuclear program because of recent revelations that scientists in South Korea had illegally experimented with producing fissile material that could be used for nuclear weapons.

A fourth round of negotiations had been expected to take place later this month in Beijing among North Korea, the United States, Japan, South Korea, China and Russia.

South Korea, a longtime U.S. ally, has been one of the leaders in the effort to coax North Korea into giving up its nuclear arms program. But the recent revelation that South Korea dabbled in nuclear experimentation as recently as 2000 could damage its moral credibility and, by extension, that of the U.S.

“There is strong suspicion that the disclosed experiments might be conducted at the instruction of the United States,” an unnamed spokesman for the North Korean Foreign Ministry said in a statement released on the official KCNA news service Saturday. “We cannot but link these cases to the issue of resuming the six-party talks.”

The New York Times reported today that some Bush administration officials are concerned that North Korea is planning a nuclear test.

But others believe North Korea’s threats and bluster are negotiating tactics to get the best possible deal for giving up its nuclear program.

“It would be hideous if they tested a weapon, but that sounds unprobable. Everyone would go over the edge and there would be no incentive to deal with them,” said a Western diplomat in Seoul, speaking on condition of anonymity.

The site of the blast is close to the Yongjori missile base where North Korea is believed to store its mid-range Rodong missiles in tunnels dug under Mt. Paektu, a peak straddling the Chinese border. The location raises the possibility that the explosion was an accident, possibly caused by rocket fuel, said Daniel Pinkston, a North Korea expert at the Center for Nonproliferation Studies in Monterey, Calif.

“If it were a nuclear explosion, there would be radioactive fallout and that would be picked up. There are detectors at the demilitarized zone, at friendly embassies in Pyongyang, on ships, and I think we would know in a day or two,” said Pinkston, who is currently a visiting professor at Seoul’s Korea University.

Efforts were underway to get the six-party negotiations back on track. Assistant Secretary of State James A. Kelly was shuttling between Tokyo and Beijing over the weekend.

Bill Rammell, a British Foreign Office minister, visited Pyongyang, the North Korean capital, as did a high-level Chinese delegation.

Some analysts said they doubted that Pyongyang would choose to conduct a nuclear test while such senior foreign officials were in North Korea.

“It’s not likely that Pyongyang would choose to explode a device during these visits,” said Li Dunqiu, secretary-general of the Korean History Study group within the Chinese Academy of Social Sciences.

Diplomats expressed pessimism about the future of the six-party process. Even South Korea’s foreign minister, Ban Ki Moon, acknowledged that “it is difficult to be optimistic.”

Times staff writers Bob Drogin in Washington and Mark Magnier in Hong Kong contributed to this report.