North Korean business people are being recalled from China following the execution of top official, Chang Song-thaek, the BBC reported quoting a South Korean report.
Leader Kim Jong-un may be purging associates of Chang, who was in charge of economic ties with China.
Kim has been pictured by state media for the first time since the execution of Chang, his uncle.
The South Korean government believes Kim Jong-un is trying to consolidate his power through a reign of terror.
The execution of the leader's uncle on Friday raised international concern about the stability of the nuclear-armed state.
North Korea has summoned back business people working out of the north-eastern Chinese cities of Shenyang and Dandong, sources told the South Korean news agency Yonhap.
They are in China to enhance bilateral trade and investment.