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.
The Israeli military attacked the Gaza Strip for a third day on Thursday night, killing two people, the Palestinian Authority's official news agency said, in another test of a fragile ceasefire agreement.
The United States cancelled a planned Budapest summit between President Donald Trump and Russian leader Vladimir Putin following Russia's firm stance on hardline demands regarding Ukraine, the Financial Times reported on Friday.
Forty-three detained local United Nations staff will face trial on suspicion of links to an Israeli airstrike that assassinated top Houthi leaders in August, the acting foreign minister of Yemen’s Houthi government, Abdulwahid Abu Ras, told Reuters.
Hurricane Melissa's confirmed death toll has climbed to 49, according to official reports, after it wreaked destruction across much of the northern Caribbean and headed towards Bermuda.
Britain's King Charles has stripped his younger brother Andrew of his title of prince and forced him out of his Windsor home, Buckingham Palace said on Thursday, seeking to distance the royals from him over his links to the Jeffrey Epstein scandal.