File picture: North Korean soldiers marching
North Korean soldiers have shot and wounded a comrade at the heavily guarded border as he successfully defected to South Korea, the South's military said.
Soldiers from the North have occasionally attempted to defect to South Korea by crossing the Joint Security Area.
However, it is rare for a North Korean soldier to survive crossing the Demilitarised Zone, one of the world's most heavily guarded strips of land.
The soldier bolted from a guard post at the northern side of Panmunjom village in the Joint Security Area to the southern side of the village, South Korea's Joint Chiefs of Staff said in a statement.
He was shot in the shoulder and elbow and was airlifted by a United Nations Command helicopter to a South Korean hospital, the Defence Ministry said.
It was not immediately known how serious the soldier's injuries were or why he decided to defect.
South Korean troops found the injured soldier south of the border after hearing sounds of gunfire, a Defence Ministry official said.
He added that South Korean troops did not fire at the North.
The defection comes at a time of heightened tension over North Korea's nuclear weapons programme and could escalate animosities between the rival countries.
North Korea has accused South Korea of enticing its citizens to defect, which the South denies.
About 30,000 North Koreans have defected to South Korea since the end of the 1950-53 Korean War, but most travel through China.
Panmunjom, once an obscure farming village inside the four kilometre-wide Demilitarised Zone (DMZ) that separates the two Koreas, is where an armistice was signed to pause the Korean War.
Jointly controlled by the American-led UN Command and North Korea, the DMZ is guarded on both sides by hundreds of thousands of combat-ready troops, razor-wire fences and tank traps.
More than a million mines are believed to be buried inside the zone.
American presidents often visit Panmunjom and other DMZ areas during their trips to South Korea to reaffirm their security commitment to the South.
US President Donald Trump planned to visit the DMZ to underscore his stance against North Korea's nuclear programme when he came to South Korea last week as part of an Asian tour.
However, heavy fog prevented his helicopter from landing at the border area.
At Panmunjom, North Korean soldiers wearing lapel pins with the images of late North Korean leaders, often use binoculars to monitor visitors from the South.
They stand only several metres away from South Korean soldiers wearing aviator sunglasses.
This makes the area a popular stop for visitors from both sides.
Areas around Panmunjom were the site of bloodshed and defection attempts by North Koreans in the past, but there have been no such incidents in recent years.