A North Korean man walked across one of the most dangerous borders in the world and into South Korean custody late Thursday.

The unidentified man, who was unarmed, crossed the heavily fortified Demilitarized Zone (DMZ), The Associated Press reported.

South Korea’s Joint Chiefs of Staff said troops tracked him near the central-west portion of the border and guided him through the mine-laced terrain before taking him into custody.

Military officials have not said whether the man was attempting to defect. The American-led United Nations Command was notified, and no unusual movement was observed on the North Korean side.

A North Korean military guard post, loudspeaker, top left, and South Korean army soldiers, bottom right, are seen from Paju, South Korea, near the border with North Korea, on June 12. (AP Photo/Ahn Young-joon)

Border incidents between the two Koreas are also becoming more frequent. In April, ten North Korean troops briefly crossed the military demarcation line before retreating after warning shots. Last year saw three similar incursions, according to The Associated Press.

Thursday’s incident involved not a group of soldiers, but a single man crossing from North Korea into the South. It is considered increasingly rare for possible defectors to choose this route; typical North Koreran defectors take a path through China instead.

Neighborhoods of North Korea’s Kaepoong village are seen from the observation post in Ganghwa, near the border with South Korea. (AP Photo/Ahn Young-joon)

Diplomatic talks between the U.S. and North Korea have been frozen since 2019, when denuclearization negotiations collapsed. Since then, Kim has poured resources into expanding his nuclear arsenal and repeatedly threatened both Seoul and Washington.

President Donald Trump has warned North Korea that the U.S. will respond forcefully to any aggression. His administration remains committed to a strong alliance with South Korea and Japan, and to keeping a close watch on Pyongyang.

The Associated Press contributed to this report.