As of 1 p.m., some 200 balloons had crossed the border to fall in various locations across the country since Tuesday night, reaching as far as the southeastern province of South Gyeongsang, according to the Joint Chiefs of Staff (JCS), as quoted by Yonhap news agency.

It marked the largest amount of North Korean balloons sent into the South, compared with previous instances between 2016 and 2018, the JCS said, adding that it expects the figure to rise.

According to reports, the trash included plastic bottles, batteries, shoe parts and even manure.

Military personnel are collecting the trash for detailed analysis.

"These acts by North Korea clearly violate international law and seriously threaten our people's safety," the JCS told Yonhap. "(We) sternly warn North Korea to immediately stop its inhumane and vulgar act."

Balloons were reportedly found in eight to nine provinces in South Korea.

Both the warring neighbours have reportedly used balloons as their propaganda tactics.

Earlier this month, a South Korea-based activist group claimed it sent 20 balloons which were carrying anti-North Korea leaflets and USB sticks containing Korean pop music and music videos across the border.

In 2020, Seoul's Parliament passed a law to criminalise the launch of anti-Pyongyang leaflets.