South Korean activists have released huge gas-filled balloons filled with socks over the border into impoverished North Korea, despite threats from Pyongyang.
The socks can be worn to help survive the harsh winter, be sold for cash or exchanged in the communist North for food that can keep a person going for a month, the campaigners say.
About 1000 pairs of socks were launched by five large plastic balloons from the northern South Korean city of Paju.
Each pair of socks was attached with a leaflet containing a "politically innocuous" message, said the Seoul-based group North Korea Peace, which has been sending socks to the North once a month over the past few months.
"We're not interested in sending political messages or sparking any troubles there. All we want is that people in the North wear warm socks over their frozen feet," Sunny Kim, a spokeswoman for North Korea Peace, told AFP.