Hyon Yong Chol was killed by firing squad using an anti-aircraft gun at a military school in front of hundreds of people in Pyongyang around April 30, the agency reported, citing a media briefing by the National Intelligence Service at its headquarters in Seoul.

Hyon “was purged for lese majeste” because he was seen “dozing off” during a military event and “did not carry out Kim’s instructions,” the agency said. It wasn’t clear what instructions Hyon failed to carry out.