North Korea has threatened to launch full-scale retaliatory military steps against South Korea in protest to the South’s use of photos of Pyongyang's leaders for target practice.

A spokesman for North Korea’s General Staff of the Korean People’s Army said in a statement Friday that all North Korean troops would gradually step up their retaliatory measures until the South apologized and penalized those responsible for the photos being used in training camps.

The North’s statement comes after a Defense Ministry official in Seoul acknowledged on Tuesday that photos of North Korea’s founder Kim Il-sung, North Korean leader Kim Jong-il and his youngest son and heir apparent Jong-un were used as shooting targets at some training camps for reserve forces. The North’s National Defense Commission had charged earlier that the North Korean leaders’ photos were being used for shooting targets at reservist training facilities.