North Korea has been laying landmines north of the Military Demarcation Line(MDL) since last month.

According to a military official in Seoul on Friday, Pyongyang has been dispatching hundreds of North Korean soldiers on a daily basis since April to set landmines within the Demilitarized Zone(DMZ).

The official said over one-thousand soldiers were mobilized on some days and heavy equipment is being deployed.

In January, North Korean leader Kim Jong-un called for step-by-step measures to completely separate the two Koreas along the border.

In response, South Korea's Joint Chiefs of Staff(JCS) said on Friday that the military is conducting surveillance and tracking the North Korean military's activities, while closely cooperating with the United Nations Command when necessary.