With North Korea found to be behind a bloody land mine explosion in the demilitarized zone last week, South Korea warned Monday that the North will be forced to pay "equally pitiless" costs for its military provocations.
  

"As previously warned on many occasions, our military will make North Korea pay the equally pitiless penalty for their provocations," Maj. Gen. Koo Hong-mo, head of operations for the Joint Chiefs of Staff, said in a warning statement to the communist country.
  

In the statement, the South Korean military also sternly urged the North to apologize and punish those who are responsible for the mine explosion.
  

The mine blast took place on the morning of Aug. 4 on the southern side of the DMZ near the city of Paju, Gyeonggi Province, while eight South Korean Army soldiers carried out a regular scouting mission there. The explosion severed the legs of two staff sergeants.
  

A South Korean investigation has found that three North Korean wooden-box mines were the cause of the blast, a provocation apparently intended to derail the joint Ulchi Freedom Guardian exercise scheduled for next week between Seoul and Washington.
  

North Korean soldiers are believed to have crossed the military demarcation line to secretly lay the mines around a South Korean military-guarded door that opens to the DMZ possibly late last month, the South Korean military said.
  

Asked what kinds of retaliation will be taken, Defense Ministry spokesman Kim Min-seok declined to elaborate, only saying that "The substance cannot be disclosed now, but we will wait and see."
  

Kim highlighted that the military will ensure the punitive action is taken against North Korea because the country's responsibility for the mine detonation has been clearly proven.
  

"This provocation is a clear violation of the armistice agreement and the non-aggression agreements between the South and the North," the JCS said also said in the statement, denouncing what it called a "nasty behavior that is unthinkable for any normal military."
  

South Korea's ruling and main opposition parties lashed out at Pyongyang's land mine explosion, calling the act a "provocation."
  

"North Korea's provocation is an unforgivable act that directly goes against the armistice agreement," said Kim Young-woo, a spokesman of the ruling Saenuri Party. "North Korea should give an explanation and apologize for today's investigation result."
  

The main opposition New Politics Alliance for Democracy also denounced the act, saying that the party will not overlook it.
  

"The party will not approve of any kind of provocation that threatens national security," said Kim Yung-rok, the party's spokesman. (Yonhap)