A United Nations human rights expert has called on the Pakistani authorities to make it a top priority to locate and protect four disappeared human rights and social media campaigners, saying no government should tolerate attacks on its citizens. <br/><br/>David Kaye, the UN Special Rapporteur on the right to freedom of expression said, by making the investigation of these disappearances an urgent priority, the Pakistani authorities can send a strong signal that they take seriously the responsibility for the life and security of all of its citizens, particularly in cases involving freedom of expression. <br/><br/>Kaye said, free expression campaigners and experts have long called for the abolition of criminal blasphemy provisions in Pakistan, which may carry the death penalty.