South Korean officials said their troops exchanged fire with North Korea on Sunday morning along the tense land border dividing the two countries.
North Korean troops fired several bullets at a South Korean guard post inside the heavily fortified border between the countries, the Joint Chiefs of Staff in Seoul said in a text to NBC News. No casualties or damage to equipment were reported.
South Korean military personnel fired two rounds in response after broadcasting a warning.
"We are in the process of taking measures to ensure that no additional situation occurs," the Joint Chiefs of staff said. It added that it was communicating with North Korea through a military line while staying prepared for further fire.
The Koreas are split along the Demilitarized Zone, which was created as a buffer. But despite what its name suggests, the DMZ is the world’s most heavily fortified border.
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U.S. Secretary of State Mike Pompeo confirmed the exchange of fire Sunday on ABC's "This Week."
"We think those were accidental. The South Koreans did return fire," Pompeo said. "So far as we can tell, there was no loss of life on either side."
Sunday's incident came a day after North Korean leader Kim Jong Un was reported to have appeared in public for the first time in nearly three weeks, rebutting rumors that he was dead or severely ill.
Asked about the photos, Pompeo said Kim's absence from the public was "not unprecedented."
"So there's not much I can share with you, other than we've seen the same images from yesterday that the world saw," Pompeo said. "It looks like Chairman Kim is alive and well."