Seoul (AFP) - North Korea has executed a vice premier for showing disrespect during a meeting presided over by leader Kim Jong-Un, South Korea said Wednesday, after reports that he fell asleep.

The regime also banished two other senior officials, Seoul said, the latest in a slew of punishments Kim is believed to have ordered in what analysts say is an attempt to tighten his grip on power.

"Vice premier for education Kim Yong-Jin was executed," Seoul's Unification Ministry spokesman Jeong Joon-Hee said at a regular briefing.

Kim was killed by a firing squad in July as "an anti-party, anti-revolutionary agitator," added an official at the ministry, who declined to be named.

"Kim Yong-Jin was denounced for his bad sitting posture when he was sitting below the rostrum" during a session of North Korea's parliament, and then underwent an interrogation that revealed other "crimes", the official told reporters.

The mass-selling JoongAng Ilbo reported on Tuesday that top regime figures had been punished, but identified the education official by a different name.

"He incurred the wrath of Kim after he dozed off during a meeting presided over by Kim," it quoted a source as saying.

"He was arrested on site and intensively questioned by the state security ministry".