North Korea has executed a vice premier and banished two other senior officials to rural areas for "re-education", according to South Korean officials.
If confirmed, they would be the latest in a series of killings, purges and dismissals carried out since North Korean leader Kim Jong Un (pictured) took power in late 2011.
Jeong Joon Hee, a spokesman for South Korea's Unification Ministry, told reporters that Kim Yong Jin, a vice premier on education affairs in North Korea's cabinet, had been executed.
He gave no further details, including why and when his ministry believes the minister was executed and how it obtained the information, but a South Korean source said the vice premier was executed by firing squad in July for unspecified anti-revolutionary and factional acts.
The official said the minister first faced an investigation because of the way he was seated during a June meeting attended by Kim Jong Un.
North Korea is a closed, authoritarian country with a state-controlled press that often makes it difficult for outsiders, and even North Korean citizens, to know what is happening in the government.
Rival South Korea, which runs several intelligence organisations mainly tasked with spying on North Korea, has a mixed record on reporting developments across the border. In May, a former North Korean military chief, who Seoul said had been executed, was found to be alive and holding several new senior-level posts.
Little is known about Kim Yong Jin, who was last mentioned by North Korea's state news agency on June 15, when it reported he attended an event celebrating the 50th anniversary of the founding of North Korea's taekwondo federation.
Kim Jong Un, believed to be his early 30s, is revered at the centre of an intense cult of personality, with state TV occasionally showing ageing senior officials kneeling before him. Last year, South Korea's spy agency said Kim had his defence chief executed with an anti-aircraft gun for complaining about him and sleeping during a meeting he had presided over.
Mr Jeong said Kim Yong Chol, a senior ruling Workers' Party official in charge of anti-Seoul spy operations, had been ordered to undertake "revolutionary re-education", in a reference to the banishment at a rural collective farm or a coal mine. Mr Jeong said another senior party official dealing with propaganda affairs, Choe Hwi, was still on a similar programme.
Seoul officials believe Kim Yong Chol, director of the party's United Front Department, orchestrated two attacks that killed 50 South Koreans in 2010, when he headed the North Korean army's intelligence agency. He disappeared from the public eye for about 50 days before the North's state media on Sunday mentioned his name in a list of officials who attended ceremonies marking Youth Day.
Kim Yong Chol was banished to a rural farm for about one month between mid-July and mid-August because of alleged high-handed attitudes and attempts to expand his United Front Department's authority too much, according to the South Korean official who spoke about Kim Yong Jin's execution. The official said Kim Yong Chol had recently been reinstated.