North Korean leader Kim Jong-un (R), flanked by his uncle North Korean politician Jang Song Thaek
North Korean leader Kim Jong-un (R), flanked by his uncle North Korean politician Jang Song Thaek, leaves a military parade to mark the birth anniversary of the North's late leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo in February 16, 2012. North Korea said on December 13, 2013 Jang Song Thaek, the uncle of leader Kim Jong Un and previously considered the second most powerful man in the secretive state, has been executed after a special military tribunal found him guilty of treason. Earlier this week the North stripped Jang of all posts, accusing him of criminal acts including mismanagement of the state financial system, womanising and alcohol abuse. Reuters

All direct descendants of North Korean leader Kim Jong-un's uncle, Jang Song-thaek, including women and children, have been executed as per the dictator's orders, reports said.

It is unclear how or when the executions were carried on, but Korea's Yonhap news agency added that children of Jang's two brothers have also been killed.

"Extensive executions have been carried out for relatives of Jang Song-thaek," a source told Yonhap. "Some relatives were shot to death by pistol in front of other people if they resisted while being dragged out of their apartment homes," the news agency added.

According to the agency, the dead include Jang's sister Jang Kye Sun, her husband Jon Yong Jin, who was also the Ambassador to Cuba, Ambassador to Malaysia Jang Yong Chol, a nephew of Jang, along with his two sons

A few relatives by marriage, who were spared the execution, have been exiled to remote village, according to reports.

"The executions of Jang's relatives mean that no traces of him should be left," a source said. "The purge of the Jang Song-thaek people is under way on an extensive scale from relatives and low-level officials."

Kim's 67-year-old uncle was executed last year after labelling him an enemy of the state, "despicable political careerist and trickster," "human scum" and "worse than a dog."

Initial reports of the execution, which were later dismissed, revealed that Jang was eaten alive by a pack of dogs.