Park Sang-Ha, who heads a group of North Korean defectors, launches anti-Pyongyang leaflets. Photo: Jung Yeon-Je/AFP

South Korea revoked the operation permits of two defector groups on Friday for sending anti-North Korea leaflets across the border after Pyongyang furiously denounced their activities and blew up a liaison office.

The move is likely to trigger debate over freedom of expression in the democratic South.  

The leaflets, usually attached to hot air balloons or floated in bottles, criticize North Korean leader Kim Jong Un over human rights abuses and his nuclear ambitions.

Seoul’s Unification Ministry said said the two groups severely hindered the government’s efforts for unification by sending the leaflets.

They also raised tensions on the Korean peninsula and put the safety and lives of Koreans living in border towns in danger, it added.

Revoking the groups’ operational permits does not make them illegal but will make it harder for them to raise money and deny them access to benefits for registered organizations.

Park Sang-hak, the leader of one of the groups, said the South Korean government had “deprived us of the most important value of democracy, which is freedom”.

Both Koreas used to regularly send leaflets to the other side, but agreed to stop such propaganda activities, including loudspeaker broadcasts along the frontier, in the Panmunjom Declaration signed by Kim and the South’s President Moon Jae-in at their first summit in 2018.

Last month, Pyongyang issued a series of vitriolic condemnations of South Korea over the leaflets, which defectors based in the South continued to send despite the agreement.

It upped the pressure by blowing up an inter-Korean liaison office on its side of the border and threatening military measures.

Seoul officials previously banned leaflet activities in border areas and filed a police complaint against the groups.

Human Rights Watch has condemned the South’s moves, calling them shameful.

“Instead of proposing a blanket ban on sending balloons with messages and materials to the North, President Moon should publicly demand that North Korea respect freedom of expression and stop censoring what North Koreans can see,” Phil Robertson, the group’s deputy Asia director, said last month.

Inter-Korean relations have been in deep freeze after the collapse of a summit between Kim and US President Donald Trump early last year over what the nuclear-armed North would be willing to give up in exchange for a loosening of sanctions.