The future of a joint industrial complex between North and South Korea remains in question, as Pyongyang blocked South Korean workers from entering the center for a second day.
Seoul expects about 200 workers to return home Thursday from the Kaesong industrial zone, which lies about 10 kilometers inside North Korea. Officials say that would leave about 600 South Koreans at the facility.
There are concerns that the workers could become trapped in North Korea, should any conflict break out. South Korea has said that military action is a last-resort option if the safety of its workers is threatened.
North Korea on Thursday renewed its threat to shut down the complex, which is the last remaining sign of inter-Korean cooperation. The facility, which opened in 2004, is also an important source of income for cash-strapped Pyongyang.
But the South Korean Unification Ministry is denying reports the North has ordered all South Koreans to leave the facility. It said the reports, which circulated early Thursday, were based on a misunderstanding of a memo sent to South Korean workers.
Pyongyang, which is angry at recent U.N. sanctions over its nuclear program, has issued near-daily threats against Seoul and Washington.