Seven South Korean staff remaining at an inter-Korean industrial park failed to return home on Thursday as they were still negotiating with North Korean officials over unpaid wages and other issues, a Seoul official said.

"The gap has closed, but there are lingering differences that will require more talks," said the unification ministry official, who declined to be identified.

The two sticking points are the amount of money South Korean companies need to pay North Korean laborers, and the need to bring back production materials and finished goods that are owned by local companies, he said.

The South Korean nationals at the Gaeseong Industrial Complex had to stay behind to discuss payment of outstanding wages for North Korean workers, tax issues and various service charges. The team is led by Gaeseong Industrial District Management Committee

(KIDMAC) chairman Hong Yang-ho.

Seoul ordered a pullout of all South Korean staff on Friday after Pyongyang repeatedly declined to accept proposals for talks to normalize operations. The North effectively shut down Gaeseong after it told all workers not to report to work on April 9.

The exact amount of money being demanded by the North has not been confirmed, but it may exceed US$10 million. This includes $7.2 million that the 123 South Korean companies should have paid the laborers in March.

The KIDMAC representatives also are demanding the North take steps to hand over finished goods and production materials still at the complex to their South Korean owners. (Yonhap News)