North Korean state-run media say the country's military chief, Ri Young-ho, has been removed from all of his official posts.
A short statement from the ruling Worker's Party says the removal of Ri -- who was a key adviser to new leader Kim Jong-Un -- was "because of illness."
The move is being scrutinized for signs about the direction in which Kim Jong-Un is planning to take the isolated nuclear-armed state.
Ri was made army chief three years ago under Kim Jong-il, the new leader's father who died in December 2011 after ruling North Korea for almost two decades.
Ri was one of seven top officials to accompany the younger Kim as he followed the hearse containing his father's body at his state funeral.
Based on reporting by Reuters, AP, dpa, AFP, and the BBC