According to Lt. Gen. Ahn Young-ho, a top official with South Korea’s Joint Chiefs of Staff, a staffer with the Ministry of Maritime Affairs and Fisheries went missing in waters 1.9 kilometers (1.2 miles) south of the Yeonpyeong Islands on September 21.
The islands lie near the maritime border between North and South Korea, and at some point, the official crossed into North Korean waters, after which, according to South Korean intelligence, North Korean forces opened fire, killing the South Korean. They later burned his body, Ahn said.
In a statement, the South Korean military said it “strongly condemns the North’s atrocities” and urged Pyongyang to provide an explanation and punish those responsible.
“In addition, we sternly warn that North Korea is responsible for the atrocities committed against our citizen,” the statement added.
The deterioration in relations came after a years-long rapprochement led by South Korean President Moon Jae-in resulted in historic meetings between himself and North Korean leader Kim Jong Un, as well as summits between Kim and US President Donald Trump.