Hundreds of South Koreans streamed out of the communist North at the weekend, expelled from a joint industrial enclave by Pyongyang in anger at the hardline policy of the conservative leader in the South, Reuters reported.
The expulsions, part of measures to tighten the border with the South, come about a week before regional powers are expected to meet in Beijing to resume talks on ending the North's nuclear arms program and compensate it with economic and energy aid.
However, a South Korean official said as many as 1,700 South Korean managers could return to the industrial zone just north of the heavily armed border from Monday, when North Korea's new border restrictions take effect.
"It appears that for the next week, as the final list of names get confirmed, there will be some flexibility," a Unification Ministry official in Seoul said on Sunday. "But the number will probably not get cut sharply."
The scaling back of the industrial park is the latest measure taken by the North since President Lee Myung-bak took office in the South in February vowing to get tough with Pyongyang and link aid to progress it makes on ending its nuclear program.
The 1,700 would be the "necessary personnel" needed to keep the factory park operating, out of the nearly 4,200 South Korean managers and officials who had previously been permitted by the North to enter it.
Some analysts saw the move as dealing a further setback to ties between the two Koreas, which are technically still at war under a truce that suspended the 1950-53 Korean War, after the North refused dialogue until Lee dropped his hardline policy.
It also deals a blow to the communist North's credibility as a business partner because South Korean firms, which have pumped hundreds of millions of dollars into the factory project, would now be reluctant to invest there.
On Friday, the last train with a sole empty cargo car crossed the border, as a rail service that moved little or no goods but was seen a symbol of reconciliation for the two states was halted after one year.
Tours to the North Korean border city of Kaesong, also started about a year ago, were suspended on Friday.
Analysts said the tours might have been viewed by reclusive North Korea as destabilizing because they allowed visitors from the South to see just how destitute their neighbor is and gave its residents a glimpse of their wealthy southern neighbors.
The Kaesong factory park, about 70 km (45 miles) from Seoul, is the only major economic connection between the two Koreas. A total of 88 South Korean firms employ more than 33,000 North Koreans there to make goods such as pots, watches and clothes.