By Ju-min Park
PAJU, South Korea, April 4 (Reuters) - Hundreds of South Koreans rejected the chance to leave factories in North Korea on Thursday that have become the centre of a bitter standoff between the two countries, running the risk of becoming hostages to keep their plants going.
For those whose commute to work already involved a trip across the world's most heavily fortified border and into one of its most repressive states, this week's tensions were another reminder of their precarious livelihoods.
It also showed how South Koreans have become largely inured to threats from their impoverished and bellicose neighbour.
On Wednesday, Pyongyang barred access to the Kaesong Industrial park, where 123 mostly small South Korean firms employ 50,000 North Korean workers to make clothing, shoes and other goods.
"I have four dependents in my family. We didn't go there for political reasons, we were there to make our living," said Kwon Bo-sun, a 44-year-old trailer driver who was waiting at the South Korean border town of Paju to see if he would be allowed to truck supplies into the zone.
Pyongyang has allowed South Korean factory managers and workers to leave Kaesong, about 5 km (3 miles) inside North Korea.
But out of 828 people who spent the night there just 222 had indicated they wanted to return to South Korea on Thursday, with the rest continuing to try to keep their factories running.
Many South Koreans waited all day on Thursday at Paju, hoping to get in. Some expressed concern that a cut in gas supplies would affect the operation of equipment at their factories. One worker who returned asked reporters not to sensationalise the standoff.
The companies are estimated to have invested around $500 million in the park since it was inaugurated in 2000.
South Korean corporate giants such as Samsung Electronics and Hyundai Motor, the sort of companies that could sustain losses from the park's closure, do not have operations in Kaesong.
The North warned again on Thursday that it would close the zone in reprisal for what it sees as "hostile" military exercises by the United States and South Korea which have been beefed up in response to Pyongyang's threats of war.
Many South Koreans are used to the rhetoric from North Korea, which remains technically at war with both the South and with the United States after an armistice rather than a peace treaty ended the 1950-53 Korean conflict.
North Korea has now staged three nuclear weapons tests, the most recent in February, which drew new sanctions from the United Nations.
It shelled a South Korean island in 2010 and is blamed for killing 46 South Korean sailors when a naval vessel was torpedoed in the same year.
Pyongyang has in the past also launched commando raids, tried to kill South Korean presidents, bombed an airliner and killed South Korean government officials in a bombing overseas.
"It is true most people involved in Kaesong do not have that sense of urgent risk to their personal safety," said a business executive with operations there who declined to be identified for fear his business could be affected.
KAESONG, A BAROMETER OF FAITH IN UNITED KOREA
The economic zone generates $2 billion a year in trade and pays an average $130 a month in wages to North Koreans who might otherwise struggle to find a job in an economy that has shrunk over the past 20 years.
It is also practically the last vestige of the "Sunshine Policy" of rapprochement between the two Koreas and a powerful symbol that the divided country could one day reunify.
Even as North Korea's propaganda machine hurled more insults at Seoul on Thursday, it appeared that a sense of solidarity between Koreans in the zone was still holding.
"When food supplies come in from the North, (they are) sharing some with the South Korean workers there," said Park Yun-kyu, an executive.
Most food supplies are usually shipped in from South Korea, which has not happened now for two days.
Other South Koreans who have been in the zone said North Korean workers had been less friendly this week.
There were brief jitters in Seoul's financial markets when one South Korean businessman said the North would close the zone on April 10.
The South's Unification Ministry, which handles inter-Korean relations, denied the reports and said the North wanted to be told of scheduled plans for workers leaving over the next week.
"The North's request to several companies for a schedule of people returning to the South by April 10 has been distorted to say the North had requested a total pullout," the ministry said.
South Korea has had to submit a list of those wishing entry to the complex three days in advance.
North Korea itself has not issued a statement on restricting entry but on Thursday again threatened permanent closure if Seoul continued to offend a country that bridles at even the mildest criticism.
"If the South's puppet conservative group and its media continue bad-mouthing ... we will be taking the stern measure of pulling out all of our workers from the Kaesong industrial zone," its KCNA news agency said.