Seoul: North Korea publicly executed two officials in early August for disobeying leader Kim Jong Un, a South Korean newspaper reported on Tuesday, in what would be the latest in a series of high-level purges under the young leader's rule, if confirmed.

Kim took power in 2011 after the death of his father, Kim Jong Il, and his consolidation of power has included purges and executions of top officials, South Korean officials have said.

Citing an unidentified source familiar with the North, the JoongAng Ilbo daily said former agriculture minister Hwang Min and Ri Yong Jin, a senior official at the education ministry, had been executed.

The report could not be independently verified, and South Korea's Unification Ministry, which handles North Korea-related matters, did not have immediate comment.

Some previous media reports of executions and purges in the reclusive state later proved inaccurate.

The report of the executions comes soon after the South said North Korea's deputy ambassador in London had defected and arrived in the South with his family, dealing an embarrassing blow to Kim's regime.

North Korea rarely announces purges or executions, although state media confirmed execution of Kim's uncle and the man widely considered the second most powerful man in the country, Jang Song Thaek, in 2012 for factionalism and crimes damaging to the economy.

A former defence minister, Hyun Yong Chol, is also believed to have been executed last year for treason, according to the South's spy agency.

The JoongAng Ilbo said the two men were executed by anti-aircraft gun at a military academy in Pyongyang.

North Korean state media described Hwang, one of the officials named, as agriculture minister in 2012, and referred to him as a vice minister of agriculture in 2014.

Hwang was killed because his policy proposals were seen as a challenge to Kim Jong Un, JoongAng Ilbo said. Ri was caught nodding off during a meeting with Kim and later investigated for corruption and showing disrespect to the leader, it added.