SEOUL, July 3, 2024 (BSS/AFP) - Trash-carrying balloons sent by North Korea across the border have disrupted more than 100 flights carrying 10,000 passengers, a South Korean lawmaker said Wednesday.

Pyongyang has floated more than a thousand balloons carrying bags of trash into the South, in retaliation for similar missives sent northwards by activists in the South, carrying anti-Kim Jong Un propaganda.

The North's balloons briefly forced a three-hour halt to flights in and out of South Korea's Incheon airport on June 26, and the multiple balloon launches over the past month have required other flights to delay takeoffs or landings -- or even to divert.

Citing new data from the transport ministry, MP Jeong Jun-ho said that 115 commercial jets have been disrupted by the balloon launches -- which began in late May -- affecting more than 10,000 passengers.

At least 15 jets, including long-haul arrivals from the United States, were forced to make alternative landings, with passengers then driven to Incheon, causing lengthy delays and inconvenience, he said in a press statement.

Hundreds of passengers on flights from San Francisco, Vancouver and Los Angeles "were slated to land at Incheon International Airport but ended up at Cheongju Airport without knowing what was happening," he said.

The disruption is "an embodiment of Korea Risk", said Jeong, referring to the term used to describe investor hesitancy over military threats from the North.

Jeong urged authorities to do more to prevent activists from sending the balloons into the North.

South Korea cannot sanction activists sending balloons across the border due to a 2023 court ruling that bans it as an unjustifiable infringement on free speech.

Relations between the two Koreas are at one of their lowest points in years, with Pyongyang ramping up weapons testing as it draws ever closer to Russia, amid accusations that it is supplying arms to Moscow to be used in the war in Ukraine.

North Korea has resorted to sending trash instead of propaganda leaflets as it did during the Cold War because it knows touting its ideology to South Koreans is "laughable", said the Centre for Strategic and International Studies in a report Monday.

"However... they should not be taken lightly. The trash-filled balloons and the damage they do is a form of soft terrorism."