Seoul warned the public on Saturday to avoid more balloons sent from North Korea and to report them to the military or police.
South Korea's military said North Korea was sending more balloons carrying "filth" across the heavily fortified border.
North Korea sent hundreds of balloons carrying trash and excrement earlier this week, calling them "gifts of sincerity" and vowing to send more. On Saturday, South Korean Defence Minister Shin Won-sik called this "unimaginably petty and low-grade behaviour".
A public message broadcasted by the city of Seoul asked the public to refrain from touching balloons "identified in the sky near Seoul" and report them as they were "being handled by the military".
Other regional governments had been asked to broadcast similar messages, the defence ministry said.
North Korea has said the balloons were retaliation for an ongoing propaganda campaign by North Korean defectors and activists in South Korea, who send balloons containing anti-Pyongyang leaflets, food, medicine, money and USB sticks loaded with K-pop music videos and dramas across the border.
A Palestinian teen has been shot dead during an Israeli military raid in the occupied West Bank on Wednesday, the official Palestinian news agency Wafa reported.
Some 287 candidates will be considered for the 2026 Nobel Peace Prize, the secretary of the Norwegian Nobel Committee said on Thursday, with US President Donald Trump likely to be among the nominees.
At least 17 migrants have died, and nine are missing after their boat broke down and drifted for eight days in the Mediterranean Sea, Libya's Red Crescent and Libyan security sources said on Wednesday.
Israel has begun taking control of aid ships bound for Gaza far from Israeli shores, Israeli army radio cited an Israeli source as saying on Wednesday.
Donald Trump discussed how to mitigate the impact of a possible months-long US blockade of Iran's ports with US oil companies, a White House official said on Wednesday, as the US president urged Tehran to 'get smart soon' and sign a deal.