A South Korean soldier stands guard at the Joint Security Area inside the Demilitarized Zone, May 9, 2023.

A South Korean soldier stands guard at the Joint Security Area inside the Demilitarized Zone, May 9, 2023. (David Choi/Stars and Stripes)

CAMP HUMPHREYS, South Korea — Around 20 North Korean troops briefly crossed into the southern portion of the Demilitarized Zone over the weekend, prompting South Korean forces to warn the intruders by firing shots and using loudspeakers, the South’s military announced Tuesday.

The North Korean troops who crossed the Military Demarcation Line at 12:30 p.m. Sunday “immediately” went back to their side of the border after the warnings, the Joint Chiefs of Staff said in a text message to reporters.

The border is covered with overgrown trees and other vegetation, making signs denoting the boundary difficult to see, South Korean army Col. Lee Sung-jun said during a news conference Tuesday. Some of the North Koreans were carrying “work tools,” he said, but declined to elaborate.

No unusual activity from North Korea was detected immediately after the incident, Lee added. The DMZ’s boundaries and the Military Demarcation Line — the actual border between the two Koreas — were established during armistice agreement negotiations to pause the 1950-53 Korean War.

The DMZ’s buffer stretches 150 miles across the peninsula and has a width of roughly 2 1/2 miles.

U.N. Command, which is responsible for upholding the armistice agreement between the two countries, did not immediately respond to a request for comment Tuesday.

The incident comes amid an uptick in tensions between North and South. On Sunday, the South’s Ministry of National Defense resumed broadcasting propaganda messages through loudspeakers deployed at the border in response to the North sending around 1,300 balloons carrying trash to the South.

The North’s state-run Korean Central News Agency reported the balloon campaign was in response to South Korean human rights groups who sent their own balloons carrying cash and household goods in hopes they reach struggling civilians. The broadcasts were paused Monday and there were unspecified indications that the North was reinstalling loudspeakers on its side of the border, the Joint Chiefs announced that day.

Gunfire is not unheard of within the heavily fortified DMZ.

On Jan. 28, 2023, a South Korean soldier accidentally fired four rounds from a KR-6 heavy machine gun during training; the rounds were believed to have landed several hundred yards south of the demarcation line, the military said at the time.

Three years earlier, North and South Korean troops exchanged gunfire between their guard posts near the border. A U.N. Command investigation was unable to determine whether North Korean forces negligently discharged their weapons; however, it found both Koreas violated the armistice agreement by firing their weapons across the border.

Kim Yo Jong, sister of North Korean leader Kim Jong Un and a senior party official, warned Monday of a “new counteraction” if the South’s military broadcasts and civilian balloons continued to transit Pyongyang’s airwaves.

“[South Korea] will suffer a bitter embarrassment of picking up waste paper without rest and it will be its daily work,” she said in a KCNA statement. “I sternly warn Seoul to stop at once the dangerous act of bringing the further confrontation crisis and discipline itself.”

David Choi is based in South Korea and reports on the U.S. military and foreign policy. He served in the U.S. Army and California Army National Guard. He graduated from the University of California, Los Angeles.

Sign Up for Daily Headlines

Sign up to receive a daily email of today's top military news stories from Stars and Stripes and top news outlets from around the world.

Sign Up Now