North Korea sent more balloons likely carrying trash toward South Korea on Sunday, the South's military said, just four days after the prior similar launch.

The Joint Chiefs of Staff said the North resumed its balloon campaign and warned the balloons may float toward Seoul and the surrounding Gyeonggi Province.

Since late May, the North has launched thousands of balloons carrying trash in retaliation against anti-Pyongyang leaflets sent across the border by North Korean defectors and activists in South Korea.

In response to the balloon launches, the South's military has been blasting daily anti-North Korean propaganda broadcasts through loudspeakers on the border since July 21. It has refrained from directly shooting down the balloons, citing safety concerns.