South Korea's military has promised "searing" consequences in retaliation for land mine blasts last week that maimed two of its soldiers on the Seoul-controlled southern part of the Korean Demilitarized Zone (DMZ).

The army's announcement didn't go into specifics about what exactly is planned, though included is the resumption of propaganda broadcasts across the border towards rival North Korea for the first time since 2004.

As a result of Tuesday's explosions, one soldier had to have part of each of his legs amputated, according to the South Korean Defense Ministry, while the other had his foot removed at the ankle. The two had been on a routine patrol near a wire fence in the southern side of the border.

In a statement, the Joint Chiefs of Staff said planting the land mines was "a clear violation of the armistice agreement and the non-aggression agreements between the South and the North.

"As previously warned on many occasions, our military will make North Korea pay the equally pitiless penalty for their provocations."

"North Korea will pay a harsh price proportionate to the provocation that North Korea made," Major General Koo Hong-mo, director of operations of the South's Joint Chiefs of Staff, said on Monday.

If Seoul acts on its vow to pipe the anti-North Korean broadcasts on loudspeakers aimed across the world's most heavily armed border, it will worsen already terrible ties between the Koreas and infuriate the North, which is extremely sensitive to any outside criticism of the authoritarian leadership of Kim Jong-un.

The DMZ has bisected the Korean Peninsula since the end of fighting in the Korean War in 1953. South Korea's military said the broadcasts planned Monday are only part of its response. It was unclear when the broadcasts would start or how long they would continue.

The US-led UN Command also conducted an investigation that blamed North Korea for the mines. "The United Nations Command condemns these violations of the Armistice Agreement, and will call for a general officer level-dialog with the Korean People's Army," the UN Command statement said.

The war between North and South Korea still technically continues because the participants have yet to sign a peace treaty.