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

South Korea fired warning shots after, Seoul says, North Korean troops crossed their border. The soldiers then went back to the North, Seoul said.

This was stated in a statement issued by the military authorities in Seoul following the latest incident with Kim Jong-un's regime. On Tuesday, at 5:00 p.m. on the Korean Peninsula, a dozen North Korean soldiers crossed the militarized border into South Korea.