The Louisianian, solely identified as "A," was detained by South Korean officials after he crossed into the 25-mile-wide Civilian Control Line without permission, according to South Korea's Yonhap News Agency.
In order to enter the restricted area, which sits just south of the heavily fortified Demilitarized Zone (DMZ) that separates the two Koreas, people must have a permit, Stars and Stripes reported.
"If it is determined that a US citizen has been detained, the embassy will provide appropriate consular services," an official with the US Embassy in Seoul told the outlet. "Privacy concerns prevent us from sharing information on individual cases."
Per Yonhap, a resident from the Baekhak Ward notified officials from the 28th Infantry Division after spotting the man in the area. "A," who was arrested an hour after officials were alerted, was later found in the Misan Ward.
South Korea's Armed Forces and National Intelligence Service have since launched a joint probe into the matter.
But this was not the only action officials were notified of on Monday.
In a separate incident, a North Korean soldier was shot by a fellow servicemember while successfully crossing into South Korea through the Joint Security Area (JSA) at the DMZ, Yonhap reported.
"A North Korean soldier defected from a guard post on the North Korean side of the JSA toward our side at 3:31 p.m.," Yonhap reported, citing a military official.
The unidentified soldier, found bleeding on the southern side of the JSA, is now being treated for gunshot wounds he received to his shoulder and elbow.
