North Korean soldiers shot at and wounded a fellow soldier who was crossing a jointly controlled area at the heavily guarded border to defect to South Korea on Monday, the South’s military said.

North Korean soldiers have occasionally defected to South Korea across the border. But it’s rare for a North Korean soldier to defect via the Joint Security Area, where border guards of the rival Koreas stand facing each other just meters (feet) away, and be shot by fellow North Korean soldiers.

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 taken to a South Korean hospital, the South’s Defense Ministry said. It wasn’t 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 South Korean Defense Ministry official said, requesting anonymity, citing department rules. South Korean troops didn’t fire at the North, he said.

The defection came at a time of heightened tension over North Korea’s nuclear weapons program, and could escalate animosities between the rival countries. North Korea has typically accused South Korea of enticing its citizens to defect, something 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 4-kilometer-wide (2 1/2-mile-wide) Demilitarized Zone that separates the two Koreas, is where an armistice was signed to pause the Korean War. Jointly controlled by the American-led U.N. 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. President Donald Trump planned to visit the DMZ to underscore his stance against North Korea’s nuclear program when he came to South Korea last week as part of an Asian tour, but his plans were thwarted by heavy fog that 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 meters (yards) away from tall South Korean soldiers wearing aviator sunglasses and standing motionless like statues. 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.

The most famous incident was in 1976, when two American army officers were killed by ax-wielding North Korean soldiers. The attack prompted Washington to fly nuclear-capable B-52 bombers toward the DMZ in an attempt to intimidate North Korea.

In 1984, North Korean and U.N. Command soldiers traded gunfire after a Soviet citizen defected by sprinting to the South Korean sector of the truce village. The incident left three North Korean soldiers and one South Korean soldier dead. In 1998, a North Korean solider fled to South Korea via Panmunjom.

(AP)