SEOUL (AFP) - North Korea's state media on Tuesday sought to whip up public support for the shock purge of leader Kim Jong Un's uncle and former mentor, as South Korea accused Kim of waging a "reign of terror".

The North confirmed on Monday that Jang Song Thaek - seen as Kim's political regent and the country's unofficial number two - had been stripped of all posts and titles, accusing him of corruption and building a rival power base.

State TV showed photos of Jang being dragged out of his seat at a meeting by two officers, in an extremely rare public humiliation of a figure who has now been demonised as a drug-taking womaniser.

The official Rodong Sinmun newspaper said citizens angered by Jang's alleged crimes, which have been laid out in unusual detail, vowed to "burn Jang to death" or "cut his throat".

"Those miscreants who sought to ruin our unity deserve a divine punishment... I want to throw Jang and his group into boiling water," it quoted Ri Yong Song, a thermal power plant worker in Pyongyang, as saying.

The newspaper, in an article titled "Merciless iron hammers for anti-party elements!" also quoted a machinery plant worker who described Jang and his faction as "human trash" who were "worse than animals".

The paper published a full front-page editorial that called for unity under Kim Jong Un, who has ruled since his father Kim Jong Il died in December 2011, warning that North Korea would "never forgive any traitors".

South Korean President Park Geun Hye on Tuesday accused the young leader of resorting to extreme violence to cement his leadership.

"North Korea is now engaged in a reign of terror while carrying out a massive purge to consolidate the power of Kim Jong Un," she told a cabinet meeting, according to her office.

Park said that cross-border relations could now become even shakier.

"The situation on the Korean peninsula and in North-east Asia is rapidly changing, and we cannot lower our guard against North Korean threats and changes in its political situation," she said.