Kim Jong-un
Kim Jong-un apparently ordered a military official to be executed with mortar rounds (pic: Reuters/KRT via Reuters TV/Files)

A high-ranking military official in North Korea has been executed - by being obliterated with mortar rounds, it has been reported.

Kim Jong-un ordered the execution of a number of military officials for drinking alcohol or having sex during the mourning period after the death of his father, Kim Jong-il, South Korean newspaper The Chosun Ilbo claimed.

A South Korean government source told the newspaper: "When Kim Jong-un became North Korean leader following the mourning period for his father in late December, high-ranking military officers started disappearing.

"From information compiled over the last month, we have concluded that dozens of military officers were purged."

Kim Chol, vice-minister of the People's Armed Forces, was said to have been executed by firing squad but reports have emerged that he was killed in a far more extreme way.

The source said that Kim Jong-un ordered the executioners to leave "no trace of him behind, down to his hair". Kim Chol was placed in a mortar target zone and obliterated.

North Korea's recently installed leader, who is regarded by some critics in the upper echelons of the military as being too young to run the country, also ordered the military to "get rid of" anyone caught misbehaving after his father's death, it was said.

"It appears that the loyalty pledged by the military did not satisfy the young leader, who is sensitive about his age," another source said.

The purges may have been suggested by the first deputy director of the General Political Bureau of the North Korean People's Army, Kim Jong-gak.

According to data obtained by Yoon Sang-hyun, from the National Assembly's Foreign Affairs, Trade and Unification Committee, at least 14 senior party government and military leaders have been executed by Kim Jong-un.

He told the newspaper: "It seems that the purges will continue for the time being, as Kim Jong-un is tightening his grip on power."