"Our military issued warnings and fired warning shots, and the North Korean soldiers retreated," a South Korean Joint Chiefs of Staff official told reporters.

Observers claimed the Pyongyang troops might have mistakenly crossed the boundary while fortifying their side with anti-tank barriers or mines.

South Korea’s military has reported it fired warning shots as troops from the North crossed the two adversaries’ shared fortified border. The breach by approximately 10 North Korean soldiers of the border into the South on Tuesday was the second such incident in 10 months,