North Korean leader Kim Jong Un is receiving treatment after undergoing a cardiovascular procedure earlier this month. That’s according to a South Korean media report, amid speculation over Kim’s health after his absence from a key anniversary event last week. That occasion marked the birthday of Kim Il Sung, Kim’s grandfather and the nation’s founding father. Daily NK, a website run mostly by North Korean defectors, cited unidentified sources inside the isolated state saying Kim is recovering at a villa after getting the procedure on April 12. The report said Kim’s health has deteriorated in recent months due to heavy smoking, obesity and overwork. A source was quoted as saying Kim had been struggling with cardiovascular problems since last August, which worsened after repeated visits to the country’s sacred mountain, Mount Paektu. The report said Kim was last seen publicly on April 11, leaving for the hospital after presiding over a meeting of the ruling Workers’ Party. Pyongyang fired multiple short-range missiles last week, which South Korean officials said were part of the Kim Il Sung celebration. Kim would usually observe these military events, but there was no report on the test at all from KCNA, North Korea’s state-run news agency. Reporting on North Korea’s leadership is notoriously difficult, given tight controls on information. South Korea’s Unification Ministry, which handles inter-Korean affairs, declined to comment on the report.