North Korea on Tuesday threatened to "hunt down" defectors as well as South Korean activist Kim Young-hwan, who was released recently after being detained in a Chinese prison for 114 days for helping them.

"We will in the future, too, never allow those abductors, terrorists and saboteurs who dare hurt the dignity of the supreme leadership of [North Korea], encroach upon its sovereignty and threaten the safety of its people to go scot-free even by scouring all parts of the earth," the Committee for the Peaceful Reunification of the Fatherland said in an English-language statement.

The North singled out as targets Kim Sung-min of Free North Korea Radio, Park Sang-hak of activist group Fighters for Free North Korea, Cho Myong-chol, a defector who became a Saenuri Party lawmaker, and Kim.

Chapter 7 of the UN Charter defines terrorism as "the existence of any threat to the peace, breach of the peace, or act of aggression." If an actual act of terror occurs, the UN Security Council passes a resolution and punishes the group that is responsible for that act. No fewer than 13 international conventions prohibit terrorism and require countries to impose sanctions against groups that commit it. But North Korea, which is a member of the UN, has pointed out specific South Korean citizens as targets of terrorism.

The North was included in Washington's list of state sponsors of terrorism every year since the bombing of a Korean Air passenger plane in 1987 but removed from the list in October 2008 after agreeing with the Bush administration to allow inspections of its nuclear facilities, and it has been kept off the list ever since.

The four men North Korea has vowed to "hunt down" have been actively involved in efforts to promote democracy in the totalitarian state. North Korea is afraid of democracy activists who know the situation in North Korea well, such as Kim, who used to be a pro-North Korean advocate of the "juche" ideology of self-reliance at university here. Cho graduated from Kim Il-sung University, Kim of Free North Korea Radio used to be a North Korean military officer, and Park's father was a high-ranking official with the North's spy agency.

The North Korean regime wields absolute power through a reign of terror, sending dissenters to concentration camps and subjecting them to torture and starvation. Such a lawless regime naturally fears outsiders who are fully aware of its weaknesses.

There are now more than 20,000 North Korean defectors in South Korea, and there is no guarantee that there are no sleeper agents among them dispatched by the North. The four activists routinely meet defectors and are constantly under threat of being attacked by North Korean agents.

North Korea has a record of terrorism. In 1983, it attacked the South Korean presidential entourage at the Aung San Cemetery in Burma, and last month it announced the geographic coordinates of South Korean media and threatened to bomb them. The fledgling Kim Jong-un regime could very well attempt to foment tension on the Korean Peninsula in order to justify its existence to its people.

The North's latest threats cannot be taken lightly. The government must do all it can to ensure the safety of the four activists North Korea has targeted and let the UN and the international community know about the North's latest terror threat.