North Korea on Thursday ordered its military to take over an industrial complex that had been run in partnership with the South and served as a a major symbol of inter-Korean cooperation near the heavily armed border. Reports say the northern country expelled the South’s workers and seized the assets of firms. Officials in Seoul said they did not know what would happen to their citizens who had not fled before North Korea’s deadline on Thursday afternoon, with reports of more than 200 South Koreans still at the facility. The Kaesong Industrial Complex is located just inside the North’s border. The move comes as tensions escalate on the Korean Peninsula: This week, Seoul suspended operations in the industrial zone, which Pyongyang called a “declaration of war” and announced Thursday that it was cutting off two key communications hotlines to its southern enemy.