SEOUL - Presidential office of the Republic of Korea (ROK) called on the Democratic People's Republic of Korea (DPRK) Tuesday to apologize for the provocation of planting landmines in the demilitarized zone (DMZ), of which explosion maimed two ROK soldiers a week ago.

"This incident was a clear provocation as North Korea (DPRK) forces illegally violated the military demarcation line and intentionally planted PMD series mines," presidential spokesman Min Kyung-wook told a press briefing.

Min said that it was in a straight violation of the armistice agreement and the non-aggression treaty, urging the DPRK to apologize for the provocation and punish those responsible for it.

The ROK said two of its staff sergeants, who were on a patrol duty on the South side of the DMZ in the west frontier, were maimed on Aug 4 following the detonation of three landmines.

The ROK's Defense Ministry said Monday that those mines were planted by DPRK forces based on a joint on-site investigation with the United Nations Command's military armistice commission.

The presidential office held an emergency meeting of National Security Council (NSC) on Saturday after receiving the investigation reports from the defense ministry, the spokesman said.

The ROK military gave a strict warning to the DPRK, saying that DPRK forces would pay a "harsh price" for the provocations.

As part of the "harsh price," the ROK military resumed cross-border broadcasts with loudspeakers for the first time in about 11 years. The propaganda broadcasts for psychological warfare have not been aired since June 2004 after an inter-Korean agreement.

Defense Minister Han Min-koo told reporters that the military resumed the loudspeaker broadcasts from Monday and additional measures would be considered in response to the provocation.

Han said the military would conduct military operations to gain initiative in the DMZ, or a buffer zone stretching some two kilometers on both sides of the frontier dividing the ROK and the DPRK.