North Korea's leader Kim Jong-un has apologised for <a href="https://www.thenational.ae/world/asia/north-korean-soldiers-shoot-and-burn-south-korean-official-1.1083037">the shooting at sea of a South Korean official</a> who was suspected of trying to defect, and whose body was later burned. South Korea's military said on Thursday that North Korean troops shot dead a fisheries official who went missing earlier this week, before dousing his body in oil and setting it on fire. The South's national security adviser said on Friday that Mr Kim sent a letter to South Korean President Moon Jae-in saying the incident should not have happened and that the man was shot as part of measures to battle the coronavirus. The North Korean leader called the incident a "disgraceful affair" and apologised "for disappointing President Moon and South Koreans", according to a statement from the presidential Blue House in Seoul. Apologies from the North – let alone attributed to Mr Kim personally – are extremely rare, and the message comes with inter-Korean ties in the deep freeze amid a stand-off in nuclear negotiations between Pyongyang and Washington. The letter of apology was issued by the department of the North's ruling party responsible for relations with the South. Reading from the letter, the South's national security adviser Suh Hoon said Pyongyang acknowledged firing about 10 shots at the man, who had "illegally entered our waters" and refused to properly identify himself. Border guards fired him in accordance with standing instructions, it said. South Korea's military said evidence suggested the 47-year-old official was attempting to defect to the North when he was reported missing from a fisheries boat on Monday about 10 kilometres south of the Northern Limit Line (NLL), a disputed demarcation of military control that acts as the de facto maritime boundary between the two Koreas. Citing intelligence sources, the military said the unidentified man appeared to have been questioned at sea, north of the NLL and about 38km from where he went missing, before he was executed on an "order from a superior authority". Troops in gas masks then doused the body in oil and set it on fire. The North's letter disputed that the man's body was set on fire. It said his body was no longer visible after the shooting and troops set his flotation device, which was covered in blood, on fire in accordance with national emergency prevention regulations. South Korea called the killing a "crime against humanity" and asked North Korea to apologise and put measures in place to prevent a recurrence of similar incidents in the future.