SEOUL, July 4, 2025 (BSS/AFP) - A North Korean who crossed the heavily fortified land border into the South has been detained and taken into custody, Seoul's military said Friday.

The North Korean managed to cross the Military Demarcation Line in the midwestern part of the Demilitarized Zone on Thursday, Seoul's Joint Chiefs of Staff said.

The MDL is the de facto border, which runs through the middle of the DMZ -- the border area separating the two Koreas, which is one of the most heavily mined places on earth.

"The military identified the individual near the MDL, conducted tracking and surveillance," the JCS said in a statement.

It then "successfully carried out a standard guiding operation to secure custody," it added.

Seoul's military said "relevant authorities" will investigate the detailed circumstances of the incident.

North Koreans are typically handed over to Seoul's intelligence agency for screening when they arrive in the South.

The incident comes after a wooden boat carrying four North Koreans drifted into waters south of the de facto maritime border in May.

Another North Korean defected to the South across the de facto border in the Yellow Sea last year, arriving on Gyodong island off the peninsula's west coast near the border between the Koreas.

Tens of thousands of North Koreans have fled to South Korea since the peninsula was divided by war in the 1950s, with most going overland to neighbouring China first, then entering a third country such as Thailand before finally making it to the South.

Defections across the land border that divides the peninsula are rare.

The number of successful escapes dropped significantly from 2020 after the North sealed its borders -- purportedly with shoot-on-sight orders along the land frontier with China -- to prevent the spread of Covid-19.

South Korea's President Lee Jae Myung, who took office last month, has vowed a more dovish approach towards Pyongyang compared with his hawkish predecessor Yoon Suk Yeol.

"Politics and diplomacy must be handled without emotion and approached with reason and logic," Lee said Thursday.

"Completely cutting off dialogue is really a foolish thing to do."