The South Korean government says it is investigating reports that North Korea’s Kim Jong-un is in a “fragile” condition after undergoing an unspecified surgical operation.

Officials from the South Korean intelligence services said they were looking into a CNN report that said the North’s leader was “in grave danger”, citing unnamed US intelligence sources.

An earlier report by Seoul-based news outlet Daily NK said Mr Kim was staying at a countryside villa outside Pyongyang while he recovered from heart surgery, and that his condition was improving.

The South’s Unification Ministry, which handles affairs relating to North Korea, said it could not confirm either report but was investigating the matter.

However, a government source said that South Korea was yet to see any “unusual signs” coming from the North regarding Mr Kim’s health condition.

They added that the North’s leader appeared to be handling state affairs as usual and that it had no information about rumours regarding his health.

According to the North’s official news agency, the ruler presided over a meeting on 11 April, in which he discussed coronavirus prevention.

Kang Min-seok, a spokesperson for South Korea’s presidential Blue House, told reporters: “We have no information to confirm regarding rumours about Chairman Kim Jong Un’s health issue that have been reported by some media outlets. Also, no unusual developments have been detected inside North Korea.”

And the Reuters news agency quoted a Chinese intelligence source as saying he did not believe Mr Kim was critically ill. Neither Chinese nor South Korean officials denied reports Mr Kim had undergone surgery, however.

Speculation about the state of Mr Kim’s health has grown since he was conspicuously absent from events on 15 April commemorating the birth of his grandfather Kim Il-sung, the founder of the nation.

The date is a national holiday and one of the most important in the North Korean calendar. Dozens of top officials attended a flamboyant military parade at the Kumsusan Palace of the Sun, Kim Il-sung’s mausoleum, but Mr Kim was nowhere to be seen.

It is notoriously difficult to glean information about the closed-off country or its dictatorial leader other than what little is proclaimed by the North’s state media.

Mr Kim’s movements were last reported in KCNA, the country’s official news agency, on 11 April, when he chaired a meeting of the ruling party’s politburo.

His absence from the 15 April events led to speculation at the time that he might be attempting to distance his own rule from the legacy of his grandfather – or perhaps that he had been struck down with coronavirus. North Korea has officially declared zero Covid-19 cases, a claim met with scepticism by experts.

Kim Jong-un: Power in pictures Show all 20 1 /20 Kim Jong-un: Power in pictures Kim Jong-un: Power in pictures Kim Jong-un rides a horse during snowfall in Mount Paektu in this image released by North Korea's Korean Central News Agency on 16 October 2019 Reuters Kim Jong-un: Power in pictures Kim Jong-un visits the newly built Pyongyang Orphans' Primary School on 2 February 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects a women's company under Unit 5492 of the Korean People's Army in November 2019 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects the test-fire of intercontinental ballistic missile Hwasong-14 at an undisclosed location in July 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un celebrates the successful test-fire of the intercontinental ballistic missile Hwasong-14 at an undisclosed location in July 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects a potato at the Samjiyon Potato Factory in North Korea in October 2018 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un rides a horse through a forest in this image released by North Korea's Korean Central News Agency on 16 October 2019 EPA Kim Jong-un: Power in pictures Kim Jong-un inspects a block of frozen fish at a processing facility in North Korea in November 2018 Reuters Kim Jong-un: Power in pictures Kim Jong-un celebrates the succeful launch of a strategic submarine-launched ballistic missile in August 2016 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un shakes hands with Donald Trump as they meet for the first time at the Capella Hotel on Sentosa island in Singapore in June 2018 Reuters Kim Jong-un: Power in pictures Kim Jong-un and Donald Trump share a glance as they meet in the Demilitarised Zone in Panmunjon, Korea in June 2019 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects mushrooms at Pyongyang Mushroom Farm AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects a super-large multiple rocket launcher ahead of a test in September 2019 Reuters Kim Jong-un: Power in pictures Kim Jong-un inspects an apple farm in South Hwanghae Province in September 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects an apple farm in South Hwanghae Province in September 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects dental wares at a newly built factory in June 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un visits Farm No 1116 in September 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un visits a motor factory in November 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un rides a horse during snowfall in Mount Paektu in this image released by North Korea's Korean Central News Agency on 16 October 2019 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects the Command of the Strategic Force of the Korean People's Army at an undisclosed location in August 2017 AFP/Getty

It is not the first time Mr Kim’s health has been a matter of speculation. In 2014, he disappeared from the public eye for more than a month – and then was pictured using a cane on his return. South Korea’s spy agency said he had undergone an operation to remove a cyst from his foot.