SEOUL (REUTERS, AFP) - South Korea's assessment is that North Korean leader Kim Jong Un did not have surgery, local news outlet Yonhap said on Sunday (May 3), citing an unidentified senior official at the presidential Blue House.

The report of the assessment came a day after Kim's reappearance following a near three-week absence that triggered intense speculation about his health.

"There were speculative reports that Chairman Kim underwent surgery citing some difference to his walk," the official was cited as saying.

"We have reasons to believe that there was no surgery, but cannot disclose such details."

Rumours about Kim's health have been swirling since his conspicuous no-show at April 15 celebrations for the birthday of his grandfather, the North's founder - the most important day in the country's political calendar.

His absence triggered a series of fevered rumours and unconfirmed reports over his condition, while the United States and South Korea insisted they had no information to believe any of the conjecture was true.

The North's official media published photographs and a report on Saturday that Mr Kim had attended the completion of a fertiliser plant, the first report of his appearance since April 11.

Mr Kim was seen in photographs smiling and talking to aides at the ribbon-cutting ceremony and touring the plant. The authenticity of the photos, published on the website of the official Rodong Sinmun newspaper, could not be verified.