The aunt of North Korean leader Kim Jong-Un appears unscathed after the shock execution of her powerful husband Jang Song-Thaek, despite strong speculation that those close to Jang could be purged.

Kim Kyong-Hui, sister of Kim's father and the country's late leader Kim Jong-Il, was named a member of the state funeral committee for a senior ruling party official who died on Friday, the official KCNA news agency said late Saturday.

Her name was listed alongside a large group of top party and military officials including defence chief Jang Jong-Nam and Choe Ryong-Hae, a close confidant of the leader and director of the military's political bureau.

News of Kim Kyong-Hui attending an official function indicates that she remains in favour with her nephew, who has been consolidating his grip on power since his father's death two years ago.

Jang Song-Thaek, once seen as the political regent of the young Kim, was executed on Thursday for corruption and plotting to overthrow the state, among other charges.

His execution -- just days after he was ousted from all his party and military positions -- marks the biggest political upheaval since the young Kim inherited power after the death of his father in December 2011.

The latest purge was staged in an extraordinarily public and dramatic manner, with Pyongyang releasing images of Jang being dragged out of a party meeting on Sunday.

Another image showed a handcuffed Jang, with bruises on his face and hands, being held by uniformed guards at the military tribunal that sentenced him to death.

South Korean President Park Geun-Hye has criticised what she called a "reign of terror" in the North to bolster Kim's leadership. Seoul's defence chief vowed to step up troop readiness against potential provocations.

Pyongyang on Sunday angrily slammed Seoul's reaction, calling it an "intolerable provocation"

"The criticisms that took issue with our resolute actions are hideous...acts of extreme hysteria aimed at further fanning inter-Korea confrontation," the North's official website Uriminzokkiri said.

"We will slap merciless hammers on the attempts by enemy forces to...challenge our dignified leadership, just like we mercilessly punished the harmful elements among us."

Park will Monday hold a meeting with top defence and national security officials to discuss the situation in the North, her spokesman said.

The meeting will involve her national security and foreign policy advisers as well as ministers handling foreign affairs, defence, intelligence and North Korean affairs.

Jang was once seen as playing a key role in bolstering the leadership of the young and inexperienced Kim. But the 67-year-old's growing political influence and power was increasingly resented by the leader, according to analysts.

Jang and Kim Kyong-Hui were once regarded as the ultimate power couple in Pyongyang, as both held key positions in the ruling party.

But Kim Kyong-Hui, 67, has been less visible in the past year, with reports saying she was seriously ill and had sought hospital treatment in Singapore.

Analysts have warned that the purge of Jang would extend to a large number of officials seen as loyal to him.

North Korean businessmen in China have been summoned back in large numbers in recent days, according to South Korea's Yonhap news agency.

The move appeared aimed at cracking down on those "classified as having connections" with Jang, who served as a key go-between for relations with China, Yonhap said Saturday.

However, analysts said Kim Kyong-Hui -- one of a handful of people with blood ties to the ruling dynasty -- will likely escape any harsh treatment.

"The whole legitimacy of Kim Jong-Un's leadership is based on blood ties," said Lee Seung-Yeol, analyst at Seoul's Ewha Institute of Unification Studies.

Kim Kyong-Hui had played a role "that backs up the legitimacy of the dynasty", Lee said.

The political standing of leader Kim would be tarnished if his aunt were targeted, said Kim Kwang-Jin, analyst at the South's Institute for National Security Strategy.

"He (Kim Jong-Un) knows if Kim Kyong-Hui is purged, it would also backfire on him in the end," he said.

Jang and Kim Kyong-Hui had reportedly been separated for years. She may have been forced to divorce him in a bid to distance herself from the purges that will ensue, said Hong Hyun-Ik, of Seoul's Sejong Institute think tank.

"The North is apparently trying to showcase that Kim Kyong-Hui still remains powerful to continue to fully support Kim Jong-Un as part of the Kim clan," Hong said.