A SOUTH KOREAN group has launched hundreds of thousands of leaflets by balloon across the border with North Korea, despite Pyongyang repeatedly warning it that it will retaliate against such actions.

Activist Park Sang-hak said his organisation floated 20 huge balloons carrying 500,000 leaflets, 2,000 one-dollar bills and small books on North Korea from the border town of Paju last night.

Park, a North Korean who fled across the border to the South, said his leafleting is part of “a struggle for justice for the sake of liberation” of North Koreans.

The move by the Fighters For A Free North Korea group is certain to intensify already high tensions between the two countries.

North Korea recently stepped up its rhetoric against South Korean civilian leafleting, and destroyed an empty liaison office on its territory as it sought to resume its psychological warfare against the South.

Villagers stage a rally against the flying of anti-North Korea leaflets into North Korea near the unification observation in Paju, South Korea

Officials in South Korea are looking into the incident and may ask police to investigate it as a potential safety threat to front-line residents.

Seoul’s unification ministry, which handles relations with North Korea, issued a separate statement expressing “deep regret” over Park’s attempt to send the leaflets.

Park called North Korean leader Kim Jong Un “an evil” and described his rule as “barbarism”, and vowed to keep sending anti-Kim leaflets.

The activist said: “Though North Korean residents have become modern-day slaves with no basic rights, don’t they have the right to know the truth?”

South Korean officials have vowed to ban leafleting and said they would press charges against Park and other anti-Pyongyang activists for allegedly raising animosities and potentially endangering front-line border residents.

In 2014, North Korean troops opened fire at propaganda balloons flying toward their territory, triggering an exchange of fire that caused no known casualties.

Park also accused South Korea’s liberal government of sympathising with North Korea or caving to its threats. His brother, another activist also formerly from North Korea, last week cancelled plans to release bottles filled with dried rice and face masks from a front-line island.

Gyeonggi province, which governs Paju, has earlier issued an administrative order prohibiting activists from entering certain border areas including Paju to fly leaflets to the North.

If Park’s leafleting is confirmed, Gyeonggi official Kim Min-yeong said the province will demand a police investigation. The penalty for violations is a year in prison or a maximum 10 million won (£6,600) fine.

North Korea does not tolerate outside criticism of its ruling family, who enjoy a strong personality cult built by North Korea founder Kim Il Sung.

Park previously said he would push to drop a million leaflets over the border around Thursday, the 70th anniversary of the start of the Korean War.

A large banner that Park said was flown to North Korea with the leaflets Monday shows the image of Kim Il Sung and accuses him of “the slaughter of (the Korean) people” and urges North Koreans to rise up against the Kim family’s rule, according to photos distributed by Park.

In recent weeks, North Korean officials have unleashed insults against leafleting activists like Park, describing them as “human scum” and “mongrel dogs”.

They said they would also take a series of steps to nullify deals to nullify tensions which were struck in 2018 with South Korea.

Yesterday, North Korea’s state media said it had manufactured 12 million propaganda leaflets to be floated toward South Korea in what it said would be the largest-ever anti-Seoul leafleting campaign.