Senior North Korean military officer Hyon Yong Chol, right, attends the fourth Moscow Conference on International Security in Moscow in this April 16 file photo. (Sergei Karpukhin/Reuters)

North Korea’s equivalent of a defense minister has been executed by antiaircraft gun for insubordination and treason — including for sleeping during a meeting in which Kim Jong Un was speaking, South Korea’s intelligence agency said Wednesday.

The report, if true, would starkly illustrate the brutal extent to which the young North Korean leader is going to consolidate power.

Gen. Hyon Yong Chol, held a variety of senior positions in North Korea’s military, most recently as chief of North Korea's People’s Armed Forces, the No. 2 military position in the country. He was executed by firing squad at a Pyongyang military school in front of hundreds of people at the end of last month, officials from the National Intelligence Service told local reporters at a briefing in Seoul.

An NIS spokesman confirmed to The Post that it believed Hyon had been executed.

The NIS delivered a similar report to lawmakers in a closed-door parliamentary session earlier Wednesday, according to the South’s Yonhap News Agency. Hyon was seen dozing off during a military event and did not carry out Kim’s instructions, Han Ki-beom, the deputy director of the NIS, told the committee. YTN, Yonhap’s television arm, broadcast photos of Hyon, sitting at a meeting two seats away from Kim, with his eyes closed.

“He was definitely purged and reliable intelligence says he was executed publicly in front of hundreds of military officers,” Kim Gwang-lim, a South Korean lawmaker who was in the NIS briefing, told reporters afterwards, according to a transcript.

“According to intelligence, Hyon was shot to death at Kangkun military school in Pyongyang,” another lawmaker, Lee Cheol-woo, added, saying that the execution showed that Kim operated a “reign of terror.”

The NIS report could not be independently verified. NIS’s claims turn out to be wrong as often as they are right. The agency had previously told lawmakers that it expected Kim to travel to Moscow for Russia’s Victory Day celebrations last weekend, shortly before the Kremlin announced he would not.

But Michael Madden, who runs the blog North Korea Leadership Watch, said Wednesday's report rang true and was the latest in a slew of personnel changes — some fatal — in North Korea.

“Hyon was a critical guy,” Madden said. “I don’t think there is a stability issue, but I think there are some internal dynamics going on."

Hyon was frequently mentioned in the official North Korean press, with a Korean Central News Agency report stating that he attended a party for the anniversary of the birth of the founder of North Korea, Kim Il Sung, in Moscow on April 15.

The last mention of him was in an April 29 report of a performance in Pyongyang. The NIS said he was executed on about April 30.

In announcing that Kim would not be attending the Victory Day celebrations on May 9, the Kremlin said the North Korean leader had “internal matters” to deal with. The NIS report suggested that this was the matter Kim had to attend to, Madden said.

“It’s no accident that we’re hearing about this after Kim Jong Un did not go to Moscow,” he said.

This report is the latest suggestion that Kim, the 30-something third-generation leader of North Korea, is tightening his grip on power. Kim, who succeeded his father, Kim Jong Il, at the end of 2011, had his uncle and mentor, Jang Song Taek, executed at the end of 2013, on grounds he had disobeyed orders and worked in secret to build up his base of power.

Since taking over the country ruled through a bizarre personality cult, Kim has ordered a series of reshuffles, purges and apparent executions as a way to consolidate his authority.

Madden said he viewed the Hyon execution as part of a series of events set off by Jang’s death in December 2013. Jang had been in charge of many of North Korea’s business dealings with China, and his demise set off a series of investigations.

Previously, Kim dismissed Ri Yong Ho, the top military leader, in July 2012, saying in a terse statement that he had been “relieved of all his posts” because of illness. Hyon was a major beneficiary of this move; he was promoted by Kim as a result.

The NIS last month told lawmakers that Kim Jong Un had ordered the execution of 15 other senior officials this year, some by machine gun, for offences ranging from corruption to watching South Korean soap operas.

North Korean defectors have said recently that executions are being carried out in increasingly spectacular style — including with high-caliber artillery — to make an example of those who fall afoul of Kim’s monolithic system.

A recent report from the U.S. Committee for Human Rights in North Korea contained satellite imagery apparently showing several people standing in front of antiaircraft machine guns at a military training area 13 miles north of Pyongyang in October last year.

But not everyone was convinced by Wednesday’s report from the NIS.

"If Hyon had been indeed publicly executed at the end of April as reported, he would have been removed from North Korean TV documentaries, but it doesn't seem to have been done,” said Cheong Seong-chang, a North Korea expert at the Sejong Institute in Seoul, speculating that the NIS had political motivations for spreading this news.

North Korea on Saturday reported test-firing a submarine ballistic missile for the first time, a launch that Seoul said could threaten the South.

Coincidentally, the reports of Hyon’s execution come on the heels of the death of another top North Korean military official — although apparently by natural means.

General Kim Kyok Sik, who was apparently in charge of a 2010 attack on a South Korean naval corvette, which killed almost 50 sailors, died Sunday of respiratory failure at the age of 77. He was suffering from cancer, according to the Rodong Sinmun, the official newspaper of the Korean Workers’ Party.

Hyon’s demise has not been officially reported in North Korea.

Seo reported from Seoul.

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