S. Korean military, UN Command conduct joint survey on DMZ blast site ahead of probe: JCS

South Korea's military said Saturday it conducted a joint survey with the U.N. Command (UNC) overseeing the inter-Korean border at the site of a suspected mine blast inside the Demilitarized Zone (DMZ) to secure an access route ahead of an on-site probe into the incident.

The joint survey by the South's Joint Chiefs of Staff (JCS) and the UNC came as they plan to carry out an on-site investigation into Monday's explosion south of the Military Demarcation Line (MDL) separating the two Koreas.

The blast occurred in two consecutive explosions, severely injuring a battalion commander and a staff sergeant of the 25th Infantry Division, a front-line unit on the western section of the heavily fortified border.

While speculation grows that an illegally planted North Korean land mine may have caused the blast, the South Korean military faces mounting criticism, largely from opposition lawmakers accusing it of dragging its feet on the investigation to align with the Lee Jae Myung government's conciliatory policy toward Pyongyang.

Dismissing the claims, the JCS has stressed that it is preparing to launch a joint probe with the UNC once the safety of all participating personnel, including soldiers who may need to revisit the high-risk site, is fully guaranteed.

Saturday's joint survey was part of such efforts to "assess the operational environment and secure an access route" for the on-site investigation, the JCS said in a message to reporters.

"The personnel deployed to the DMZ evaluated the overall operational environment, including assessing the safety of movement routes, and checking the status of surveillance and communication," the JCS said.

The survey team was comprised of about 20 personnel, including those from the JCS' on-site investigation task force -- led by the JCS vice chairman -- the UNC's Military Armistice Commission and relevant investigative agencies, the JCS said.

Some service members involved in the blast volunteered to participate in Saturday's survey, the JCS added.

"Our military has been steadily making preparations to ensure a thorough joint on-site investigation with the UNC, while prioritizing the safety of our service members," the JCS said.

"Based on the findings, we plan to objectively and transparently explain the cause of the incident and the investigation results to the public," it said.

Rep. Han Dong-hoon, who's been staging a one-person protest in front of the defense ministry compound this week, asserted Saturday that the South's military had rejected an earlier UNC proposal to launch the on-site probe on the day of the blast.

Han claimed the government has now moved up the investigation to Sunday, instead of Tuesday as originally planned, following growing public outcry.

The JCS has not yet confirmed a date for initiating the on-site investigation.