North Korea continues to lambaste South Korea over leaflet campaigns carried out by North Korean defectors in the South.

Following a statement issued by the director of the North's United Front Department late Friday threatening of "painful times ahead," the Rodong Sinmun, the official newspaper of the North’s ruling party, on Saturday also denounced the flying of leaflets across the border.

The paper said that slander and insult against the supreme leader is more dangerous than large-scale joint military drills.

In a commentary piece, the paper said the provocative act, referring to leaflets, is the most vicious challenge and declaration of war against the regime that can never be forgiven.

Pyongyang warned that additional measures will follow, saying the complete cutoff of communication lines with the South is only the first step.