Korea's military has conducted a joint on-site investigation with the U.N. Command (UNC) to look into the cause of a suspected mine blast inside the Demilitarized Zone (DMZ) last week, officials said Sunday. The Joint Chiefs of Staff (JCS) said a survey team comprising some 40 personnel reached the vicinity of the suspected explosion site inside the DMZ and surveyed the area using mine detectors. The joint probe comes just six days after the explosion occurred south of the Military Demarcation Line (MDL) separating the two Koreas, leaving two officers seriously injured.