South Korean police have blocked a group of human rights activists from sending balloons attached with radios into North Korea.
South Korea has delicate relations with its Northern neighbour
The activists said they wanted to help the people of the secretive communist state find out what was happening in the outside world.
Veteran German activist Norbert Vollertsen was reportedly injured in the ensuing scuffle.
Douglas Shin, a Korean-American rights campaigner who took part in the attempted launch, told the BBC that the activists were not aware they were acting against the South Korean authorities.
They "cheated us into believing this was OK to do", Mr Shin told the East Asia Today programme.
"But when we got there it was a different story," he said.
Asked if he thought the alleged about-face was related to upcoming six-nation talks on North Korea's nuclear arsenal, Mr Shin said: "It's all politically connected".
It is hoped that the talks, which start in Beijing next week, will help break the political deadlock on the Korean peninsula.
'Thirsty for information'
The activists were aiming to launch more than 20 helium-filled balloons across the Korean border.
Each balloon was carrying about 20-25 small transistor radios.
Officers stopped the activists' truck as they approached the border town of Cholwon, saying the air-drop was not authorised by the South Korean Government.
"Norbert tried to fill up just one balloon as a token, and they pre-empted it by... swarming over him," Mr Shin said.
Mr Vollertsen was later taken to a nearby hospital, complaining of a leg injury.
The campaign was aimed at overcoming North Korea's strict ban on outside broadcasts.
North Korean radios and televisions can only tuned in to government channels, which feature mostly army
music or gushing praise for leader Kim Jong-il.
"We are doing this because North Korean media is awful. There is no news at all - only propaganda," Norbert Vollertsen told the BBC's World Today programme on Thursday, before the attempted launch took place.
"The ordinary people are thirsty for information because... silence is killing North Korea," he said.
Mr Vollertsen is a 45-year-old German doctor, who was once honoured in North Korea for his humanitarian work there, but was expelled in 2000 after condemning the country's human rights record.