South Korea sent two helicopters to battle a wildfire inside the Korean Demilitarized Zone (DMZ), Seoul’s military said Friday, adding it had warned North Korea in advance of its firefighting mission along the heavily armed border area.

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 said troops aired warning broadcasts and fired warning shots after approximately 10 North Korean soldiers crossed the military demarcation line in the demilitarized zone.