North Korean leader Kim Jong-un ordered front-line soldiers to become "human bullets" and "bombs" to protect him, the state media reported Saturday, amid rising concerns over potential political instability in the communist state.

The Korean Central News Agency reported Kim made the comments while observing military training of two Army units, without elaborating on the location and time of the event.

Kim ordered the soldiers to have "unshakable faith" to "protect the leader unto death in the spirit of becoming human bullets and bombs and in the self-blasting spirit," the KCNA reported in an English dispatch.

The martial arts training event was seen as part of the communist regime's efforts to consolidate Kim's grip on power and draw loyalty from the military, amid political unrest in light of the execution of the young leader's powerful uncle Jang Song-thaek earlier this month.

"After watching their training, he expressed great satisfaction over the fact that the soldiers are fully prepared to defend the socialist country as firm as an iron wall and highly appreciated their success in the training," the report said.

He also "gave important instructions which would serve as guidelines for bolstering up the combat capability," it noted.

Among the top military cadres accompanying the young ruler were Choe Ryong-hae, the director of the military's political department, Minister of State Security Kim Won-hong and other senior party officials, the report said.

Concerns remain high over North Korea's stability after the Dec. 12 execution of Jang, who had played a key role for Kim, to consolidate his grip on power.

Kim, believed to be around 30, took power two years ago following the death of his father, Kim Jong-il.

Seoul and Washington have been closely watching the North amid fears that Pyongyang could carry out provocations as part of its strategy to forge internal unity following the political upheaval. (Yonhap News)