South Korea has begun propaganda broadcasts in retaliation for North Korea's nuclear test, including the sweet, girlish voice of artist IU and other K-pop hits.

The broadcasts of anti-Pyongyang propaganda across the rival's tense border began today, believed to be the birthday of North Korean leader Kim Jong Un.

The broadcasts will draw a furious response from North Korea, which considers them an act of psychological warfare and is extremely sensitive to any outside criticism of the authoritarian leadership of Kim.