North Korean businessmen in China have been summoned back to their country in large numbers to touch off speculation that Pyongyang may be preparing for more executions for those who had close ties with Jang Song-thaek, sources familiar with the issue said Saturday.

The businessmen worked out of the northeastern Chinese cities of Shenyang and Dandong to facilitate trade between the two countries and attract Chinese investment in North Korea, according to the sources.

The top North Korean official in charge of promoting economic ties with China is believed to have been Jang Song-thaek, the once-powerful uncle of North Korean leader Kim Jong-un.    

With Jang's execution on Thursday, however, North Korea appears to be cracking down on those loyal to him by summoning them back to their country, the sources said.

Jang was executed immediately after a special military tribunal found him guilty of treason, according to the North's state media. 

"Large numbers of North Korean businessmen in Shenyang and
Dandong have gone home in a hurry this week," said one source, who
declined to be identified.

"Judging from their numbers and the fact that it was so sudden, it doesn't appear to be related to the second anniversary of (the death of former North Korean leader) Kim Jong-il on Dec. 17," the source said, referring to the late father of the current leader.

According to another source, Norea Korea plans to summon all of its officials and staff from China in stages.

"The ostensible reason will be to educate them on the government's policies, but (in fact), those classified as having connections to Jang Song-thaek will never be able to go abroad again and will be purged," the source said, also requesting anonymity.

By Kim Ji-hyun and news reports

(Yonhap News)