North Korea's latest round of its balloon campaign involved around 500 balloons carrying scrap paper and plastic sheets, including those that fell on the presidential office compound in the capital, South Korea's military said Thursday.

In what marked the second of its kind this week alone, North Korea launched the trash-carrying balloons the previous day, as the South Korean military blared anti-Pyongyang broadcasts in full scale through its border loudspeakers in response to the repeated balloon launches.

Some 480 balloons fell mostly in Seoul and the northern area of nearby Gyeonggi Province, the Joint Chiefs of Staff said, while an analysis of the fallen objects showed they did not present a danger. As of 8 a.m., there had been no balloons detected floating midair, it added.

Wednesday's launch came just three days after the North floated around 500 similar balloons Sunday as part of its balloon campaign that began in late May in a tit-for-tat move against anti-Pyongyang leaflets sent by North Korean defectors and activists in the South.

In response, South Korea briefly conducted propaganda loudspeaker broadcasts on June 9 for the first time in six years before turning them off in an apparent bid to prevent the situation from spiraling out of control.

After partially resuming the loudspeaker operations last week, the military has conducted the propaganda broadcasts on all the fronts in a stepped-up approach.

North Korea has bristled against the loudspeaker campaign, as well as anti-Pyongyang leaflets sent by South Korean activists, on fears that an influx of outside information could pose a threat to the Kim Jong-un regime.

Last week, Kim Yo-jong, the powerful sister of the North's leader, warned of "gruesome and dear" consequences over continued leaflet campaigns.

In 2014, the two Koreas exchanged machine gun fire across the border after the North apparently tried to shoot down balloons carrying propaganda leaflets critical of North Korea. (Yonhap)