The South's Joint Chiefs of Staff (JCS) earlier said Pyongyang launched flying objects, which were seemingly trash-laden balloons, to Seoul, noting that they were carried by westerly winds.
The JCS warned people to be aware of the balloons and their contents as they were descending to the ground. It also asked people to stay away from fallen balloons and report them to nearby police and military bases upon sighting.
The balloons were discovered and collected in the compounds of the South's Ministry of National Defense and presidential office in Yongsan District, central Seoul.
According to the PSS, they identified trash on the ground in the Yongsan presidential office compound through cooperation with the JCS.
“Military experts dealing with chemical, biological and radiological threats have found that there were no hazardous materials contained,” the PSS said in a statement, adding that they are jointly monitoring the situation with the JCS.
The South Korean military has been operating loudspeakers toward the North since Sunday after Pyongyang floated trash-laden balloons to Seoul on the same day.