North Korean leader Kim Jong Un is in firm control of his government but hurt his leg taking part in a military drill, a source with access to the secretive nation's leadership said, playing down speculation over the 31-year-old's health and grip on power in the nuclear-capable nation.

North Korea's state media, which usually chronicle Kim's activities in great detail, have not mentioned any public appearances since he attended a concert with his wife on Sept. 3. The official KCNA news agency indicated he did not attend an important political anniversary on Friday.

In the previous two years, Kim marked the anniversary of the founding of North Korea's Workers' Party with a post-midnight visit to the Pyongyang mausoleum where the bodies of his father and grandfather are interred.