North Korea has accused South Korea of firing 450 machine gun rounds at a flock of birds earlier this week, dismissing Seoul's claim that it fired warning shots because of an object flying across the border.
The North's general staff said the South's firing was a "reckless military provocation" aimed at promoting hostility towards Pyongyang and maintaining a confrontation on the Korean peninsula.
It was also a "stop-gap measure to check the war-weariness sweeping the puppet army in the face of the rapidly developing nuclear and ballistic rocket technology" of North Korea, the general staff said in a statement carried by state media.
It said North Korea will closely watch how the South's "confrontation hysteria" would develop.
Seoul said its military fired an unspecified number of warning shots on Tuesday after detecting an object flying across the border.
They later said it was probably a balloon carrying propaganda and that North Korean leaflets were found at the border.
The Koreas face off across the world's most heavily armed border, and their militaries occasionally trade gunfire and accuse each other of provocation.
Relations between the Koreas are at one of the lowest ebbs mainly due to the North's nuclear and missile programmes. The US has 28,500 troops in South Korea to deter potential aggression from the North.