North Korean border guard units received orders at 1AM on the night of the 18th to close the border with China with immediate effect.
An inside military source told Daily NK this morning, “At 1AM on the night of the 18th a ‘Special Guard’ order was handed down to the unit. All officers who had finished work were recalled to the base and have been on emergency duty ever since.”
“At the time even commanding officers did not know about the contents of the order, and as per the order to completely close the border, normal patrols in groups of two were stepped up to groups of four. We only learned that the General had died from special broadcasts,” the source added.
Thus, it is clear that the North Korean authorities took steps to avert civilian unrest and potential mass defection attempts by shutting down the border and reinforcing patrols prior to announcing Kim’s death.