SEOUL - South Korean activists launched about 600,000 anti-North Korean leaflets across the border on Tuesday, a move that will anger Pyongyang which insists Seoul should forcibly prevent such events.
The leaflets were sent with helium balloons from a park in the border town of Paju by a North Korean defector group to mark the sinking of a South Korean warship four years ago.
The naval corvette Cheonan sank with the loss of 46 lives on March 26, 2010 near the disputed Yellow Sea border. The South accused a North Korean submarine of torpedoing the ship -- a charge Pyongyang has angrily denied.
The packages dispatched over the heavily-militarised border also contained 2,000 one dollar US bills and 700 DVDs detailing human rights abuses in the North.
Such exercises are quite common, but this was the first since the two Koreas held rare high-level talks last month that resulted in an even rarer agreement.
Included in the accord was a commitment, which the North had pushed hard for, by both sides to stop trading verbal insults.
The "no slander" clause was always going to be problematic, as Pyongyang argues that it extends to the media and private groups, while Seoul insists it has no power to censor the press or prevent non-government groups or individuals from exercising freedom of speech.
South Korean police have enforced bans on leaflet launches in the past, but for civilian security reasons, citing threats by North Korea to fire shells at the event sites.
There were no specific threats this time, although Pyongyang has repeatedly pressed Seoul to prevent the balloon launches.
"We will never yield under pressure or threat," Park Sang-Hak, a leading organiser of Tuesday's event, told AFP.
"Our activity is not designed to aggravate ties but to liberate North Koreans from dictatorship and let them know about the truth," he said.
Military tensions have been simmering on the Korean peninsula for weeks as South Korea holds annual joint military exercises with the United States.
North Korea has responded with a series of short-range missile and rocket tests.