The South Korean military says North Korea sent about 160 trash-laden balloons over the South Korean border Wednesday afternoon and Wednesday night.

As of Thursday morning, the Joint Chiefs of Staff says about 30 of the balloons have landed in Seoul and the northern part of Gyeonggi Province, carrying paper trash, plastic bags and bottles but no hazardous materials.

The latest launch is the 21st in a campaign that started May 28 in response to anti-Pyongyang leaflets sent via balloon by defectors’ groups in South Korea. 

The North also launched trash balloons Saturday and Sunday, the first two days of the Chuseok holiday weekend.