North Korea barred entry to a joint industrial complex it shares with the South for a second day today, the South Korean Unification Ministry said, but would allow 222 South Korean workers to leave the zone through the day.

However, after the 222 South Korean workers leave between 10 a.m. and 5 p.m., another 606 South Korean workers will remain in the Kaesong complex.

North Korea has threatened to shut the complex, one of the impoverished North's few sources of ready cash, as part of a tense standoff with Seoul and Washington.

"222 South Korean workers will leave (Kaesong) at the time of their choice along with 131 vehicles," said Park Soo-jin, a spokeswoman at the ministry. The gates between North and South Korea will open for the workers 10 times on Thursday.

The ministry is in charge of handling inter-Korean affairs.

South Korea has had to submit a list of those wishing entry to the complex three days in advance since North Korea shut all of its official communication lines with South Korea, the United States and the United Nations last month.

The South Korean government has urged its citizens to leave the zone.