North Korea apparently recalled scores of trade officials from abroad around the time leader Kim Jong-un's uncle Jang Song-taek was ousted and executed.
According to a source in Beijing, the North in late October ordered trade representatives and workers in China, Malaysia, Singapore and other countries to return to Pyongyang. Most of them came back before Jang was executed last week.
Another source said the North Koreans appear to have been summoned to Pyongyang for the second anniversary of former leader Kim Jong-il's death and end-of-the-year meetings. But the source added that officials who had ties to Jang "may be purged."
Among many crimes, the regime accused Jang of selling coal and other minerals at knockdown prices in trade with other countries, and officials implicated in the charges are likely to be punished.
According to another source, North Korea sent out letters about Jang's execution to its ambassadors around the world saying they should keep calm and perform their duties as usual. The ambassadors were told that they should return home if recalled but can leave their families behind.
The source said the move appeared aimed at preventing them from defecting.