North Korean sweet wrappers and packets of crackers made at a factory once visited by leader Kim Jong Un were seen by AFP reporters on streets in the South Korean capital Wednesday.

The nuclear-armed North has sent thousands of balloons carrying bags of trash southwards since May, in a tit-for-tat propaganda war between the two Koreas, with Seoul blasting K-pop and anti-regime messages from loudspeakers along the border in return.

South Korea's military warned of a fresh batch of balloons early Tuesday, including several that hit the president's downtown compound, and AFP reporters in Seoul found piles of apparent North Korean garbage on the streets later that day.

The balloons are typically cleared up quickly by South Korean authorities, but a small portion of one balloon's payload appeared to have been left behind.

"It's not right. It's inhumane," 72-year-old Joo Joung-rin told AFP, pointing to the garbage.

Another woman in her seventies who declined to give her name said "It's all very scary."

Pyongyang has described its balloon blitz as retaliation for anti-regime propaganda balloons sent northwards by activists in the South.

But Joo said the activists were sending "medicine and rice" to the North. Activists have told AFP that they sent paracetamol during the Covid pandemic, along with US dollars.

"I don't think it is right that they are sending trash," in return she said, postulating that it was "revenge" for the South's economic success.

- Soap and noodles - ==================== AFP identified the wrappers of fruit jellies with manufacturing information that indicated they had been produced in Potonggang District in Pyongyang.

There were also packages from strawberry castella cakes and sesame seed crackers which listed their production factory as the "Chungryoo corn processing plant."

Kim visited the factory in 2015 after its establishment, saying it would be the "standardised model factory in the food industry."

The trash also included instant noodle packets and wrappers of powdered soap made at the "Bonghwa soap factory" -- with the description on the wrapper claiming it was an "energy-saving" soap due to it using less water.

"Bonghwa soap" is reportedly a popular soap brand in North Korea, and, according to state media, late leader Kim Jong Il once inspected the soap factory, personally testing the soap to see if it lathered properly. The state-run Korean Central News Agency said this showed "the great general's infinite love" for the people.

The trash "looks like a payload of unused but recently produced labels -- probably from various factories or a label printing company -- in North Korea," said Chad O'Carroll, head of Seoul-based specialist site NK News.

"Compared to the scrap papers seen in other payloads, in this case it looks like relatively high-end packing material from some premium North Korean consumer goods lines," he told AFP.

It is possible this kind of trash could have been included in the balloons with "some intent to show South Koreans that there is modern and sophisticated consumer product availability," in the North, he added. (AFP)