SEOUL, May 26 (UPI) -- The U.S.-led United Nations Command announced Tuesday that it had finished its investigation into a gunfire exchange between North and South Korean forces inside the Demilitarized Zone in early May and was not able to determine whether the initial shots fired by the North were accidental or deliberate.
The exchange occurred on May 3, when four bullets from the North Korean side of the DMZ hit a South Korean guard post in the center of the 160-mile-long buffer zone that divides the Korean Peninsula, prompting South Korean soldiers to return fire. No casualties were reported.
Afterward, South Korean officials said they believed the gunfire from the North was accidental, a position later echoed by U.S. Secretary of State Mike Pompeo on ABC's This Week.
The UNC investigation, which was conducted with the cooperation of the South Korean military but not the North, stopped short of reaching that conclusion.
"The investigation determined the [Korean People's Army] committed an Armistice Agreement violation" when it fired four rounds of small arms fire on the South Korean guard post, a statement released Tuesday said. "However, the investigation was unable to definitively determine if the four rounds were fired intentionally or by mistake."
The Korean People's Army are the military forces of North Korea. The North was given the opportunity to participate in the probe but declined, the UNC said.
"UNC invited the Korean People's Army to provide information on the incident, and while the KPA acknowledged receipt of the request, they have not offered a formal response," the UNC statement said.
The armistice agreement, signed in 1953 by the UNC, North Korea and China, brought about an end to hostilities in the Korean War. A formal peace treaty has never been signed, leaving the two countries still technically at war.
The UNC investigation determined that South Korean forces responded with two volleys of gunfire and two broadcast warnings 32 minutes later. The return fire also violated the armistice agreement, the UNC said.
"The UNC determined that both the KPA and the [Republic of Korea] army committed armistice agreement violations with unauthorized small arms fire across the military demarcation line," Col. Lee Peters, a UNC spokesman, said in a video posted to the command's Facebook page.
The Republic of Korea is the official name of South Korea.
A military accord signed by the two Koreas at a Pyongyang summit in September 2018 led to the removal of 11 guard posts by each side in the DMZ, but dozens of fortifications remain.
There have been numerous gunfire exchanges in the DMZ over the years, including in 2017 when a North Korean soldier defected across the Joint Security Area in the truce village of Panmunjom, where soldiers from both sides stand face to face.
The United Nations Command was created in 1950 as a U.S.-led coalition of American, South Korean and international forces fighting to defend South Korea during the Korean War. Its primary role in recent decades has been to enforce the armistice agreement that has remained in effect since the end of hostilities in 1953.
"Based on the investigation's comprehensive findings, UNC personnel will engage in follow-on discussions with both sides to encourage an implementation of measures to prevent a recurrence of Armistice violations," the command's statement said.