South Korea’s military said Monday an explosion that seriously injured three soldiers in the Demilitarized Zone (DMZ) seven days earlier was “highly likely” to have been caused by a North Korean mine, citing preliminary evidence.

During a briefing at the Defense Ministry Headquarters in Seoul at 8:30 p.m. KST, ROK Joint Chiefs of Staff (JCS) Vice Chairman Lt. Gen. Kwon Dae-won said investigators found several indications pointing to a North Korean mine in the explosion.

“Based on the field investigation conducted so far, we assess that the cause of the mine explosion was highly likely to be a North Korean