North Korea defense chief
North Korea has officially confirmed the purging of its defense chief, Hyon Yong Chol. South Korean intelligence said that he had been executed in April. In this photo -- Hyon delivers a speech during the 4th Moscow Conference on International Security (MCIS) in Moscow April 16, 2015. Reuters/Sergei Karpukhin

North Korea has officially confirmed the purging of its defense chief, Hyon Yong Chol, two months after South Korean intelligence said he was executed for disrespecting leader Kim Jong Un by falling asleep during an official meeting, a Seoul official said Monday, according to the Associated Press (AP). The news comes a day after Gen. Pak Yong-sik was confirmed as the North's new defense minister.

Hyon was reportedly executed by anti-aircraft fire in April for disloyalty to Kim, South Korea's National Intelligence Service told lawmakers in May. Since then, the North’s state media had been silent about Hyon's disappearance. Pak’s appointment as the new defense minister, however, confirmed Hyon’s replacement and purging, Jeong Joon-Hee, a spokesman for South Korean Unification Ministry, said Monday, according to AP.

Hyon worked for many years under Kim’s father and predecessor, Kim Jong Il. He continued to serve as a high-ranking military officer after the elder Kim died in late 2011 and his son took over. Hyon had apparently questioned Kim’s power and also complained about his policies in the past.

Since Kim took power in 2011, he has executed over 70 officials, according to South Korea’s Yonhap News Agency, which cited that nation's intelligence service. The executions, which are often carried out by heavy artillery, have been criticized by human rights groups.

"The gut-wrenching viciousness of such an act would make 'cruel and unusual punishment' sound like a gross understatement," the U.S. Committee for Human Rights in North Korea said, in a statement in April, referring to reports of previous executions. "Given reports of past executions this is tragic, but unfortunately plausible in the twisted world of Kim Jong Un's North Korea."