China’s foreign ministry on Saturday urged North and South Korea to remain calm and safeguard the peace as tensions rise over a proposed protest in the demilitarized zone, state media reported. The comments came after North Korea warned that it may fire on South Korean activists who are planning to launch 200,000 balloons carrying leaflets criticizing the North Korean regime from the demilitarized zone that separates the countries. This would be the fifth time that South Korean activists have released the balloon messages since Kim Jong Un succeeded his father, Bloomberg reported. North Korea regards the leaflet drops as psychological warfare and an attempt to topple its regime. South Korean Defense Minister Kim Kwan Jin said they were prepared to “completely destroy” the origin of a North Korean attack.