An explosion near the inter-Korean border killed a South Korean national on Sunday, a government official confirmed to NK News, in an area where landmines have detonated in the past.

The accident happened on Sunday morning in Cheorwon County near the Civilian Control Line (CCL), south of the border with North Korea and around 44 miles (71 kilometers) from Seoul, according to the official. Authorities are investigating the source of the explosion.

The military has yet to confirm what caused the explosion, but multiple South Korean media reports state it was likely a mine laid down during the Korean