South Korea first got indications of an explosion in North Korea last week from a satellite that showed a "peculiar cloud" but it is too early to say whether it was a bomb, a South Korean official said today.
The senior official told Reuters indications pointed to an explosion some time between Wednesday evening and Thursday morning, but more analysis was needed to determine what it was.
"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."