Two South Korean soldiers have been severely injured in a suspected landmine explosion while patrolling the inter-Korean demilitarized zone (DMZ).

The blast took place on the southern side of the four-kilometer (2.5 mile)-wide DMZ on Tuesday, with Kim Min-seok, the South Korean Defense Ministry spokesman, saying it took place during a search operation at the DMZ.

The South Korean soldiers’ legs were reportedly blown off in the explosion.

More than a million mines are believed to have been planted along the common border.

“Although it seems that the incident was a land mine explosion, we quickly took immediate actions and it has been reported that the injuries are not life-threatening,” Kim said of the injuries of the two South Korean soldiers.

The wounded soldiers have been sent to a military hospital for treatment.

“There is no possibility of North Korea’s involvement,” said a military official, whose name was not mentioned in reports.