North Korea on Saturday sent a new round of trash-laden balloons towards the South, Seoul's military said, after anti-Pyongyang activists in the South said they had lofted balloons with leaflets against leader Kim Jong Un across the border.
The announcement came hours after Seoul's military said it was on alert for a new filthy salvo arriving from North Korea, as the tit-for-tat balloon blitz revved up once again.
"North Korea is again floating (suspected) balloons carrying trash towards the South," the Joint Chiefs of Staff said in a statement, advising the public to report any balloons to authorities and refrain from touching them.
The Seoul city government, as well as officials in Gyeonggi province, also sent a similar text alert to residents on Saturday, warning about the balloons.
North Korea sent hundreds of balloons in two waves last week with bags of trash into the South, describing them as retaliation for anti-Pyongyang propaganda balloons sent the other way.
Pyongyang said it would stop last Sunday but days later, a South Korean group called "Fighters for Free North Korea" said it had sent 10 balloons with thumb drives containing K-pop music and 200,000 leaflets condemning Kim's rule.
Another group, comprising North Korean defectors, also said it had sent 10 balloons on Friday with 100 radios, 200,000 anti-Pyongyang leaflets, and thumb drives containing a speech by South Korean President Yoon Suk Yeol.
Jang Se-yul, the leader of the second group, told AFP on Saturday that his organisation would not stop its balloon campaign, "whether Kim Jong Un sends trash-carrying balloons again or not".
Last year, South Korea's Constitutional Court struck down a 2020 law that criminalised the sending of anti-Pyongyang propaganda, calling it an undue limitation on free speech.
Experts say there are now no legal grounds for the government to stop activists from sending balloons into North Korea.
South Korea's unification ministry said Saturday that the issue is "being approached in consideration" of last year's court ruling.
Kim's powerful sister Kim Yo Jong mocked South Korea for complaining about the balloons last week, saying North Koreans were simply exercising their freedom of expression.
- 'Crash Landing on You' -
Last week, the North Korean balloons landed in a number of locations in the South, and were found to be carrying garbage such as cigarette butts, cardboard scrap and waste batteries.
In response, South Korea completely suspended a 2018 military deal with the North, which was meant to reduce tensions between the neighbours.
Authorities in Seoul have condemned the North's balloons as a "low-class" act and threatened countermeasures that it said Pyongyang would find "unendurable".
Activists in South Korea have long sent balloons northwards, filled with anti-Pyongyang propaganda, cash, rice, and Korean TV series on thumb drives.
These have always infuriated North Korea, whose government is extremely sensitive about its people gaining access to South Korean pop culture.
Kuensaem, another South Korean activist group, told AFP that it threw 500 plastic bottles into the sea on Friday near the border with North Korea.
The bottles were filled with rice, cash and a USB drive with a South Korean TV series "Crash Landing on You" -- which features a romance between a wealthy South Korean heiress and a North Korean army officer.
The group has been sending such materials to the North twice a month since 2015.
"We were just doing what we've been doing for a long time to help North Koreans who are starving," the group's leader Park Jung-oh told AFP Saturday.
Tensions over the duelling propaganda have boiled over in dramatic fashion in the past.
In 2020, blaming the anti-North leaflets, Pyongyang unilaterally cut off all official military and political communication links with Seoul and blew up a disused inter-Korean liaison office on its side of the border.