SEOUL — South Korean activists said on Thursday that they had sent 10 balloons loaded with anti-Kim Jong Un leaflets and K-pop music into North Korea, in response to hundreds of trash-filled balloons from Pyongyang.

North Korea has said its recent balloon blitz — carrying bags of garbage such as cigarette butts and plastic waste — were retaliation for previous missives sent by the activists.

Pyongyang called off its campaign on Sunday, but has warned it would restart if more balloons came north.

Past propaganda tit-for-tats have had real-world consequences for inter-Korean relations.

South Korea has called the latest provocation from its nuclear-armed neighbor "irrational" and "low class" but, unlike the North's spate of recent ballistic missile launches, the trash campaign does not violate United Nations sanctions on Kim's isolated regime.

The defector group Fighters for Free North Korea announced on Thursday that they had launched 10 balloons northward carrying 200,000 leaflets and 5,000 USB flash drives containing South Korean pop music and television shows, as well as thousands of $1 bills.

A photograph released by the group showed an activist holding up a large poster with photographs of Kim Jong Un and his sister and chief regime spokeswoman Kim Yo Jong.

"Enemy of the people Kim Jong Jun sent filth and trash to the South Korean people, but we the defectors send truth and love to our fellow North Koreans!" the poster says.

The same activist group sent balloons carrying about 2,000 USB drives containing songs by South Korean singer Lim Young-woong, as well as other K-pop and K-dramas, into the North on May 10, they said earlier this week.

North Korea is extremely sensitive about its people gaining access to the South's flourishing popular culture.

Kim Yo Jong last week mocked South Korea for complaining about its balloons, saying North Koreans were simply exercising their freedom of expression — and warning that Pyongyang would retaliate proportionately if more balloons materialized.

South Korea's parliament passed in 2020 a law banning the sending of anti-Kim leaflets across the border, as then-president Moon Jae-in sought engagement with the North.

But the Constitutional Court struck down the law last year, calling it an undue limitation on free speech, and there are now no legal grounds for the government to block the balloons, lawyer Yoo Jung-hoon told Agence France-Presse (AFP).

"While there could be political criticisms that such acts do not lead to improved lives of North Koreans, there is no legal basis for the authorities to force civic groups to stop," he said.

Propaganda wars

Pyongyang's sending of garbage balloons amounted to "despicable provocations that any normal country would inevitably be ashamed of," South Korean President Yoon Suk Yeol said in a Memorial Day speech on Thursday. "The government will not sit idly by amid such provocations."

Yoon's remarks came two days after he fully suspended a 2018 tension-reducing military deal with the North in response to the trash-carrying balloons.

The move will allow the South to resume live fire drills and restart loudspeaker propaganda campaigns along the border with the North.

The broadcasts infuriate Pyongyang, which has previously threatened artillery strikes against the loudspeaker units unless they were switched off.

"As Kim Yo Jong said they would react in proportion to anti-North leaflets from the South, Pyongyang is likely to send (more) balloons," Hong Min, a senior analyst at the Korea Institute for National Unification in the South's capital Seoul, told AFP.

"Then Seoul is expected to resume loudspeaker broadcasts along the border next week, to which the North could respond militarily," he said.