North Korea has confirmed to its overseas diplomatic missions that its defense minister, Gen. Hyon Yong Chol, was executed, a Seoul daily reported on Monday, citing a source in Beijing.

North Korea recently informed embassies in China and elsewhere of Hyon's execution and listed several instances of his "disobedience," the report in the Chosun Ilbo said.

The country's leader, Kim Jong Un ,"believes dozing off or getting distracted in a meeting is worse than opposing his decisions," the source was quoted as saying, backing up the speculation Hyon aroused Kim's anger after being caught dozing off in a meeting.

Hyon was reportedly unable to answer a question Kim asked in the meeting because he had been asleep and also disobeyed an order the leader gave, though what the order was is not known, the report said.

In May, South Korea's intelligence organization told lawmakers that the reason given for the purge was that Hyon, 66, had shown disrespect to Kim, including being caught dozing off during a military meeting on April 24-25 and not implementing instructions from the leader.

In a move to secure his grip on power, Kim has purged a number of senior officials, including his uncle and de facto No. 2 leader, Jang Song Thaek, and former general staff chief Ri Yong Ho, since taking control of the nation upon the death of his father Kim Jong Il in late 2011.