A North Korean soldier was shot and wounded by fellow soldiers Monday while defecting to South Korea at the border village of Panmunjeom, located in the demilitarized zone that divides the two countries, according to the South Korean military.

The Joint Chiefs of Staff said the soldier defected from a guard post in front of Panmungak, North Korea's main building in the Joint Security Area, a small strip of land in the truce village where troops from both sides stand face-to-face.

The incident, which occurred at 3:31 p.m., is extremely rare as North Korean troops stationed in the JSA are believed to be chosen for their loyalty, sometimes being children of the elite.

Local media said South Korean soldiers found the defector collapsed and bleeding from gunshot wounds to the elbow and shoulder about 25 minutes later, some 50 meters south of the military demarcation line near Freedom House, South Korea's main building there, and dragged him to safety.

The defector, unarmed and wearing a uniform of low rank, was then rushed to hospital by a helicopter of the United Nations Command, which oversees the armistice on the Korean Peninsula.

Media published photographs of a patient, presumed to be the wounded soldier, being transferred to the operation room at Ajou University Medical Center in Suwon, just south of Seoul, on Monday evening.

There was reportedly no exchange of gunfire between the Koreas since the defector was shot while still on the North Korean side of the military demarcation line and the bullets did not cross over to the South Korean side.

South Korea's military has strengthened vigilance in the wake of the incident and remains prepared for any situation, the Joint Chiefs of Staff said.

In February 1998, a North Korean soldier, reportedly with the rank of captain, similarly crossed the military demarcation line into South Korea at Panmunjeom.

Also Monday, a U.S. citizen was arrested by South Korean police in a military-controlled area just south of the 250-kilometer-long, 4-km-wide demilitarized zone between the two Koreas, in what appears to be an attempt to enter North Korea, Yonhap News Agency reported.

It said the 58-year-old man from Louisiana, only identified as "A," was seized at 9:55 a.m. in the border county of Yeoncheon, 62 km north of Seoul after a villager alerted the army to his presence north of the Civilian Control Line.

Broadcaster Arirang reported that he had arrived in South Korea three days earlier and was attempting to enter North Korea for what are being described as "political purposes."