Beijing’s national security arm in Hong Kong on Wednesday condemned “external hostile forces” for exploiting the deadly Tai Po fire that killed at least 159 people, as police arrested a man after he allegedly made derogatory online comments about the victims. In a strongly worded post, a spokesman for the Office for Safeguarding National Security condemned “a small clique of external hostile forces” for “stirring up trouble and taking advantage of the chaos” in the aftermath of the fire. The...