In June last year, North Korean troops violated the border three times, prompting South Korea to fire warning shots. The incidents occurred when the Koreas were embroiled in Cold War-style campaigns like balloon launches and propaganda broadcasts, but they didn’t develop into a major source of tensions.

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 fired warning shots on Monday after approximately 10 North Korean soldiers crossed the heavily fortified border separating the two countries, officials said. According to the South's Joint Chiefs of Staff,