An August 9, 2007 article in the London daily Al-Sharq Al-Awsat presented the views of six Al-Azhar sheikhs on the permissibility of kidnapping and holding hostages. According to all six, Islam forbids kidnapping civilians, holding them hostage, or harming or threatening to harm them.
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The following are excerpts from the article: 
"It Would Be a Profound Offense to Islam and to the Muslims if [the Name of] Islam Became Associated with Actions of This Sort"
Asked whether Islam permits holding hostages, Dr. Ja'far 'Abd Al-Salam, secretary-general of the Union of Islamic Universities and former vice-president of Al-Azhar University, replied: "Islam does not permit actions of this kind, which contradict the principles of justice and compassion that Islam has brought to all mankind…
"Islamic shari'a allows restricting someone's freedom only [in punishment for] a crime committed by that person…
"Actions of this kind have been unknown throughout the 14 centuries of Islamic history. There is nothing in the shari'a to justify them. It would be a profound offense to Islam and to the Muslims if [the name of] Islam became associated with actions of this sort – for Islam is against oppression, no matter what the nationality or the religion of the oppressed."
Dr. 'Abd Al-Fattah Idris, a professor of comparative jurisprudence at the Al-Azhar Shari'a and Law Department, also said that it is forbidden to kidnap anyone – Muslim or non-Muslim – and to hold him hostage in order to pressure certain parties or make demands, such as a demand to release prisoners. In support of his position, he cited Koran 6:164, which says, "No one shall bear the load of another" and "Each soul is reckoned with only on its own account." The meaning of this verse, he explained, is that one should only be punished for one's own actions. Thus, holding someone hostage in order to exert pressure on his or her country is not permitted, even if one is at war with that country. Idris added that it is forbidden to endanger a hostage or terrorize a hostage, or threaten him with death.
Kidnapping Individuals Who Are Aiding Enemy Forces is Permissible; These Individuals are Subject to Islamic Laws Regarding Prisoners of War
Dr. 'Abd Al-Mu'ti Bayoumi, a member of the Al-Azhar Academy for Islamic Research, likewise said that Islam forbids kidnapping civilians and holding them hostage. As for the question of who is considered a civilian, he said that it is permissible to kidnap individuals who are aiding enemy forces, since such aid is considered hostile action. Those individuals would then be subject to the Islamic laws regarding prisoners of war.
Dr. Ahmad 'Abd Al-Rahim Al-Sayih, a professor at Al-Azhar and a member of the High Commission on Islamic Affairs in Cairo, said that kidnapping foreign nationals, whether Muslim or non-Muslim, and holding them hostage is contrary to the tenets of Islam and has no support in the Koran or the hadith. Citing the verse "We have honored the children of Adam…[Koran 17:70]," he argued that Allah has honored all human beings and it is therefore forbidden to do anything that violates a person's honor, including kidnapping and holding hostages, and humiliation and torture. Al-Sayih called holding hostages "a barbaric practice," and condemned in particular the publication of the hostages' photos, characterizing it as un-Islamic.
Kidnapping of Noncombatants is Forbidden; Captured Combatants Are Considered Prisoners of War, and Must Not Be Killed
Professor of Islamic jurisprudence Al-Sayyid 'Abd Al-Sami' argued that kidnapping civilians was a form of rebellion against Allah (baghy), and therefore was ruled out by Koran 16:90: "Allah commands justice, good behavior towards others, and giving to one's kinsfolk, and he forbids lewdness, wrongdoing, and rebellion [against Allah]."
'Abd Al-Sami' added that kidnapping is permitted under a declared state of war, but that nevertheless it is, as an act of war, subject to various restrictions specified by shari'a. Thus, kidnapping of noncombatants such as women and children is still forbidden. Moreover, he said, captured combatants are considered prisoners of war, and must not be killed.
Al-Sami' said: "As kidnapping is considered an act of war, it is forbidden to kidnap anyone when not in a state of active war. [When someone is kidnapped during a state of war], he is [considered] a prisoner of war whom it is forbidden to kill, and he is destined to be set free [in the future]… In addition, it is not permitted to kidnap innocent people or enemy civilians – those whom it is forbidden to target with acts of war. Civilians, as defined by Islam, are non-combatants: women, children, and the elderly…"
"It is Unjust for the World to Judge Islam By the Behavior Of Muslims and Not By Its Teachings"
'Abd Al-Sami' added that the Prophet Muhammad had also forbidden the killing of laborers, including "anyone who receives a wage for services not connected to fighting, like factory workers, doctors, hospital workers, etc."
On holding hostages in order to have demands met, 'Abd Al-Sami' said: "It is not permitted to hold enemy civilians hostage and threaten to kill them because of something that others do or fail to do, [acts] for which they are not responsible and which they cannot prevent."
Lastly, Al-Azhar professor Dr. Muhammad 'Ali Al-Nawahidi said: "The injustice with which some oppressed Muslims are faced drives them, perhaps, to create new means of defending themselves, and to carry out quality operations, such as kidnappings, as a means to achieve their demands… But these actions, which achieve political goals, should not be attributed to Islam, nor should one search for jurisprudential rules that can justify them… It is unjust for the world to judge Islam by the behavior of Muslims and not by its teachings, its principles, and its program for making the world a better place."
 Al-Sharq Al-Awsat (London), August 9, 2007.