By Kang Seung-woo

North Korea threatened to attack South Korean activists, Monday, for sending anti-Pyongyang leaflets over the inter-Korean border.

The threat by the Committee for the Peaceful Reunification of Korea (CPRK) came three days after a conservative civic group flew about 10,000 leaflets to the North from Cheorwon, Gangwon Province, located close to the border.

The leaflets featured an "execution list after Korean unification" that included North Korean leader Kim Jong-un and the North's party officials and military brass, along with Kim's wife, Ri Sol-ju.

"We regard the leaflet distribution as an apparent act of war and are running out of patience with it. Such a small action can lead to the destruction of the group," the CPRK said.

"The leaflets carry unacceptable and offensive crap. It is another military provocation."

The organization also said that the South Korean government is behind the campaign.

"The leaflet campaign cannot be conducted without protection from the spy agency, the defense ministry or the unification ministry," it said.

The leaflet distribution has long been a major source of tension between the two Koreas, leading to an exchange of heavy machine-gun fire between the two countries on Oct. 10 last year.

Angered by the leaflets, mainly flown by North Korean defectors, the reclusive country cancelled a second-round of inter-Korean high-level talks, scheduled for late October or early November.