Uganda’s interior minister died suddenly on his return trip from South Korea early this month, its government has said, prompting Seoul’s probe into the rare case.

Gen. Aronda Nyakairima, who was 56, died in-flight on Saturday while heading to Dubai for a transfer following a visit to Seoul upon the invitation of the Korea Foundation.

After a postmortem examination, the cause of death was found to be acute heart failure, a news report suggested. KF officials reportedly said that he complained of a stomachache during his four-day stay but did not want medical treatment.

A former top commander of Uganda’s military credited with contributing to the 2006 ouster of notorious warlord Joseph Kony, Nyakairima took charge of internal affairs in 2013.

He was “a dedicated servant,” the east African country’s Prime Minister Ruhakana Rugunda said in a statement earlier, calling his death a “tragic and huge loss to the country.”

By Shin Hyon-hee (heeshin@heraldcorp.com)