Trash carrying ballons from North Korea float over Seoul, Oct. 4. Yonhap

North Korea launched some 320 trash-carrying balloons toward South Korea on Friday, the South's military said, marking the second launch of its kind this week.

The Joint Chiefs of Staff said it discovered some 120 trash bundles dropped around parts of Seoul and its surrounding Gyeonggi Province after the latest launch that began in the early hours of the morning.

It said the bundles consisted of household garbage, such as paper, plastic bags and plastic bottles, while no hazardous substances have been detected.

The latest launch marked the 24th of its kind since Pyongyang began the balloon campaign in late May. It last launched more than 150 trash balloons toward the South on Wednesday.

South Korea's military has vowed to take "stern" military measures should North Korea "cross the line" with its ongoing trash balloon campaign or inflict serious damage to the South Korean people.

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. (Yonhap)