South Korea unleashed a high-decibel propaganda barrage across its border with North Korea on Friday in retaliation for its nuclear test, a step that has angered the isolated North in the past.
Seoul decided to restart the broadcasts against Pyongyang after Pyongyang announced this week that it had successfully tested a hydrogen nuclear device.
The broadcasts, in rolling bursts from walls of loudspeakers at 11 locations along the heavily militarised border, blare rhetoric critical of the North Korean regime as well as "K-pop" music, ratcheting up tension between the rival Koreas.
A male announcer could be heard from South Korea telling North Koreans that Kim Jong Un, the leader of their impoverished country, and his wife wear clothes costing thousands of dollars.
Another message said Kim's policy to boost both the economy and its nuclear programme was unrealistic. The nuclear test was also discussed; "The nuclear test is making North Korea more isolated and turning it into the land of death."
Footage from South Korean TV shows South Korean soldiers preparing loudspeaker broadcasts to begin playing from noon (0300 GMT). A female radio host is then heard saying "towards unification and future," and "greetings our comrade North Koreans."
North Korea boosted troop deployments in front-line units on Friday, and South Korea raised its military readiness to the highest level at locations near the loudspeakers.
The South vowed to retaliate against any attack on the equipment, raised its cyber security alert and cancelled tours of the Demilitarised Zone on the border.
The sound from the speakers can carry for 10 km (6 miles) into North Korea during the day and more than twice that at night, Yonhap reported.