In its first official reaction to the death of Otto Warmbier, North Korea on Friday denied it cruelly treated or tortured the 22-year-old college student who it detained for more than a year and who died days after being released in a coma.

Pyongyang’s response was published by the state-run Korean Central News Agency. North Korea released Warmbier last week for what it described as humanitarian reasons and he died Monday in a hospital in his hometown of Wyoming, a suburb of Cincinnati. His funeral was held on Thursday.

His family and others blamed North Korea for his condition. But the reclusive country claimed it, not Warmbier, was the "biggest victim" in the case. "The fact that Warmbier died suddenly in less than a week just after his return to the U.S. in his normal state of health (indicates this) is a mystery to us as well," North Korea's foreign ministry said.

North Korea convicted Warmbier last year of stealing a political banner and was sentenced to fifteen years hard labor. He was released and returned in a coma to the United States on June 13 and died six days later.

"Our related institutions are treating criminals who committed crimes against (our) republic strictly based on domestic law and international standards, and Warmbier was no different,” the comments published by KCNA said. Pyongyang also criticized South Korea for using Warmbier’s case to seek the release of other detainees.

Three Americans and six South Korean nationals are still detained in North Korea.

The response did not include any details about what caused Warmbier to fall into a coma or other details about how he was treated during his detention. North Korea previously said that shortly after his conviction Warmbier contracted botulism, a bacteria commonly associated with food poisoning, and was given a sleeping pill.

Last week, Dr. Daniel Kanter, a University of Cincinnati Health neuroscientist, described Otto Warmbier’s brain as severely damaged everywhere.