Seoul/Washington, Sept. 12 (Reuters): A huge explosion rocked North Korea last week but US and South Korean officials said today it was unlikely to have been a nuclear weapons test despite the appearance of a 'peculiar cloud' over the area.
South Korea first got indications of the blast from a satellite, but it was too early to say whether it was a bomb, a senior South Korean official said. It probably occurred between Wednesday evening and Thursday morning.
'The weather overall at the time was cloudy but there was a peculiar cloud, a cloud that was different from any other,' said the official, who asked not to be identified. 'We cannot confirm whether it had the characteristics of a mushroom cloud.'
Secretary of state Colin Powell said there was 'no indication that that was a nuclear event of any kind. Exactly what it was, we're not sure.' Asked on ABC's This Week if North Korea has tested a nuclear device, Powell said, 'No.'
'We don't think, at this point, that it was a nuclear event. But we're looking at it and we'll get further analysis,' national security adviser Condoleezza Rice said on CNN's Late Edition.'
North Korea is believed to be developing nuclear weapons ' Washington has said it may have one or two or even more already. In October 2002, US officials said North Korean officials admitted to a clandestine uranium enrichment programme that could be used to develop nuclear weapons and that violated its international commitments.
Rice played down sightings of mushroom cloud. 'There are all kinds of reports and there are all kinds of assessments that are going on. Maybe it was a fire, some kind of forest fire,' she said.
South Korea's Yonhap news agency said a mushroom cloud up to 4 km in diameter was seen after the blast in an area near missile bases in Ryanggang province in the remote northeast near the border with China. Yonhap said it appeared much stronger than a train explosion that killed at least 170 people in April.
South Korea's Chosun Ilbo newspaper said the site was 10 km southwest of the Yongjori missile base at a point 30 km from the China frontier. The mountainous area is off-limits to outsiders, including aid workers.
The base has tunnels for storing, deploying and launching medium-range Rodong missiles, according to defector reports. The North has said nothing yet about a blast but often notes events long after they happen ' and sometimes not at all.
The New York Times reported in its editions today that the Bush administration had received recent intelligence reports that some experts believed could indicate North Korea was preparing to conduct its first nuclear weapons test explosion.
Powell, who appeared on several morning news programs, said the US was monitoring activity at potential nuclear sites. 'We have been watching it. We can't tell whether it's normal maintenance activity or something more. So it's inconclusive at this moment, but we continue to monitor these things very carefully,' he said on the Fox News Sunday programme.
The news broke as South Korea, Japan, China, Russia and the US were trying to persuade North Korea to resume talks on its nuclear ambitions. The North, which threatened at earlier talks to test an atomic bomb, has said it doubts more negotiations will help.