North Korea on Thursday threatened to close a joint industrial park in Gaeseong one day after it barred South Koreans’ entry, fueling concerns about their possible detention.

Pyongyang’s official media said its Wednesday decision resulted from Seoul’s conservative politicians and news outlets “speaking nonsense that we would not be able to do anything with the Gaeseong Industrial Complex.”

“Military provocations against the complex mean a self-destruction of the traitor forces,” a spokesman of the Committee for the Peaceful Reunification of Korea said in a report from the North’s Korean Central News Agency.

“The industrial district’s closure is nearing reality under the current condition with the puppet forces abusing it as a venue for fratricidal confrontation.”

Propaganda website Uriminzokkiri TV claimed that the regime has refrained from shutting down the complex so that South Korean businesses and employees would not lose their livelihoods.

“It is not us but the South Korean puppet forces and petty firms who benefit from the joint factory zone,” it said.

“If the puppet forces continue to churn out remarks hurting our dignity, the grave step of a lockout will be taken immediately.” 

The reports are apparently aimed at dismissing a widespread view in the South that the communist regime would not permanently close the Gaeseong complex, which is a major source of hard currency.

About 54,000 North Koreans there work for South Korean companies mostly in the labor-intensive sector such as textile, clothing and car parts. Industry data show that together they earn at least $80 million a year, two-thirds of which is believed to revert to state coffers.

On March 30, the Central Special Direct General Bureau in charge of the industrial park threatened to abrogate the last remaining inter-Korean project if the South “attempts to impair our dignity at all.”

Some Seoul officials and media reports continued to downplay North Korean threats nonetheless, citing a 2009 case.

Also in protest against annual South Korea-U.S. military drills, Pyongyang had cut off its military hotline with Seoul and blocked South Koreans’ entrance to the industrial park. But the hotline was restored after 12 days and the ban lasted only five days.

With some 800 countrymen remaining in the North, the government is striving to ensure their safety, activating its emergency round-the-clock contact system and some 1,300 civilian communication lines.

Even in the 2009 incident, a Hyundai Asan Corp. employee was detained for 136 days.

Cheong Wa Dae’s national security office convenes a meeting every morning to discuss the situation with presidential secretaries on foreign affairs and security, unification and crisis management, spokeswoman Kim Haing said.

Earlier in the day, more than 520 officials and workers gathered in Paju, Gyeonggi Province, hoping to cross the border but were turned back again. Around 220 people are expected to come home throughout the day for the weekend.

Pyongyang has requested some firms at Gaeseong to submit their lists of remaining workers who plan to return to the South by April 10, the Unification Ministry said.

Concerned about any manufacturing delays and subsequent revenue shortfalls, many executives and workers are postponing their departure and asking for more time.

“People inside are anxious because the situation is more serious than usual,” a 37-year-old female surnamed Kwon told reporters as she arrived at the Gyeongui Highway Transit Office in the border city.

“It’s been all right so far because all companies have food materials good for one week. But there will be a huge problem if this situation drags on.”

Industry organizations issued a statement and urged the North to lift the entry ban, saying the complex “must maintain normal production activities in all circumstances.”

“A couple of factories have suspended operations because of a lack of gas supplies,” said Kim Ki-mun, chairman of the Korea Federation of Small and Medium Businesses, at a news conference in Paju.

“We’re extending our stay to work as long as we can while monitoring the situation, and hoping the problem will be positively resolved.”

By Shin Hyon-hee  (heeshin@heraldcorp.com)