Kim Yong Jin, a vice premier in North Korea’s cabinet, has been executed for being “an anti-party, anti-revolutionary agitator,” South Korean officials said Wednesday. Two other senior officials have been banished to rural areas for reeducation, the officials added.

According to the officials in Seoul, these are the latest executions and demotions of top North Korean officials since Kim Jong Un assumed power in 2011.

“Kim Yong Jin was denounced for his bad sitting posture when he was sitting below the rostrum” during a session of the reclusive country’s parliament, according to a South Korean official, who declined to be named. The vice premier was then interrogated during which his other crimes were revealed, the official told reporters. He was allegedly executed by a firing squad.

South Korean daily JoongAng Ilbo reported Tuesday that the official, who served as vice premier for education, was executed but the newspaper identified him as Ri Yong Jin, and not as Kim Yong Jin. It reported that another official, former agriculture minister Hwang Min, was also executed because his policy proposals were viewed as a challenge to the North Korean leader.

Meanwhile, Kim Yong Chol, the head of the North’s United Front Department that looks over inter-Korean relations, was ordered to carry out “revolutionary reeducation,” Seoul’s Unification Ministry spokesman Jeong Joon Hee said. Another top official dealing with propaganda affairs, Choe Hwi, was also reportedly put on “revolutionary reeducation” program.

The Associated Press, however, noted that South Korea that has several intelligence organizations mostly spying on North Korea has a mixed track record for news from the secretive country. In May, a former North Korean military official, who South Korea had said was executed, was found to be alive and holding several senior-level positions.

The latest alleged execution comes after North Korea’s deputy ambassador in London reportedly defected and arrived in South Korea with his family. Last year, Seoul’s spy agency said that a former North Korean defense minister, Hyon Yong Chol, was executed for treason.