North Korea reacted furiously Tuesday after activists in South Korea launched anti-Pyongyang leaflets over the border, calling them "human scum" who exposed the hypocrisy of Seoul's calls for dialogue.
A small group of activists had launched tens of thousands of leaflets by helium balloon on Sunday, just days after the North sent a letter to the presidential office in Seoul demanding such exercises be halted.
"The south Korean puppet regime let human scum ... scatter leaflets defaming (North Korea)," a spokesman for the Committee for the Peaceful Reunification of Korea said in a statement.
The statement, carried by the North's official KCNA news agency, said the operation amounted to "an unpardonable mockery and insult," and warned of unspecified retaliatory measures.
The spokesman said it also ran contrary to the conciliatory spirit of the ongoing Asian Games in the South Korean port city of Incheon -- in which the North is competing.
"The south Korean puppet regime should bear in mind that it can no longer pay lip service to such words as 'dialogue'," he added.
The leaflets blamed the North's ruling Kim dynasty, including current leader Kim Jong-Un, for the vast gap between the impoverished, isolated North and economically advanced South.
South Korean activists -- many of them defectors from the North -- have been carrying out leaflet launches for years.
At times of heightened cross-border tensions, the South Korean authorities have stepped in to stop the exercises for fear of retaliation.