SEOUL : North Korea is pressing ahead with plans to evict hundreds of South Koreans from a joint industrial estate as cross-border ties worsen further, Seoul officials said on Tuesday.

The communist state demanded staff data from the estate managers hours after it announced severe curbs on movements across the heavily fortified frontier, the unification ministry in Seoul said.

The North said Monday it would suspend tours to the city of Kaesong, halt a historic cross-border rail service, severely restrict other frontier crossings and cut the number of South Koreans working at the Kaesong industrial estate near the city.

It told South Korean estate managers to supply details of who would stay and who would leave by Tuesday morning, said ministry spokesman Kim Ho-Nyoun.

"We're responding to this request," he said.

It was unclear exactly how many staff would have to leave. The North has said half of the "unnecessary" South Korean staff at a joint management office or involved in construction and services should leave by December 1, when the border restrictions come into force.

As of early Tuesday, a total of 1,592 South Koreans were at Kaesong, which was built with the South's money just inside North Korea as a symbol of reconciliation.

They include 750 managers at 88 firms, 201 people at nine construction companies and 553 employees of Hyundai Asan and its suppliers. The private firm operates all joint projects and tours in the North.

The impoverished North has indicated it would not force the closure of the industrial estate, which earns it tens of millions of dollars a year.

But the restrictions could severely hamper operations at Kaesong, where more than 32,000 North Koreans each earn around 60 dollars a month working for South Korean-owned factories.

The border curbs follow months of icy relations, including threats by the North over cross-border propaganda leaflets dropped by Seoul activists.

The North says the border restrictions are in response to Seoul's failure to honour agreements reached at inter-Korean summits in 2000 and 2007.

South Korean President Lee Myung-Bak, a conservative who took office in February, promised to take a firmer line with the North after a decade-long "sunshine" engagement policy under his liberal predecessors.

He has said he would take another look at summit pacts that envisage joint economic projects costing tens of billions of dollars.

Lee, quoted by Yonhap news agency on his plane en route from Peru to Los Angeles, said his government would continue a policy of "reconciliation, co-prosperity and co-existence" with the North.

Prime Minister Han Seung-Soo expressed regret at developments.

"As to the various inter-Korean agreements and declarations, the government has repeatedly expressed its willingness to engage in dialogue to discuss the implementation of them," Han said.

"We sincerely hope that pending issues should be resolved through dialogue at the earliest possible date."

- AFP/al