North Korea on Wednesday delayed the entry of South Koreans to a joint industrial complex in a rare move amid high tensions on the Korean peninsula, the South's Unification Ministry said.
"North Korea has not yet given us the daily permission for the entry of 484 South Koreans into Kaesong today," a South Korean Unification Ministry spokeswoman told AFP.
The border crossing usually takes place at 8:30 am (2330 GMT), but there has been no word from the North's officials for almost an hour, she said.
The delay sparked fears the North could carry out its threatened shutdown of the Seoul-invested industrial estate, which has continued to run during previous crises on the peninsula.
Border crossings for Kaesong, which lies 10 kilometres (six miles) inside North Korea, have been functioning normally despite soaring tensions in recent weeks between the North and the South.
The operating stability of the complex is seen as a bellwether of inter-Korean relations, and its closure would mark a clear escalation of tensions beyond all the military rhetoric.