North Korea reportedly publicly executed two high-ranking officials with an anti-aircraft gun this month, including one who dared to challenge Kim Jong Un’s leadership, a South Korean newspaper reported Tuesday. The JoongAng Ilbo daily cited an unidentified source as saying Hwang Min, a former agriculture minister, and Ri Yong Jin, a senior official at the education ministry. Ri was said to have been killed for falling asleep during a meeting with the North Korean leader. If confirmed, the executions would be the latest in a string of purges of top officials. The report comes after North Korea’s deputy ambassador in London defected to South Korea, a move that drew scorn from authorities in Pyongyang. Kim reportedly reacted to the defection by ordering that any officials who allowed it to happen be executed.