Muslim clerics widely denounced Islamist militants in Syria over the burning to death of a Jordanian pilot, saying such a form of killing was considered an abomination under Islam, no matter the justification. Islamic State militants released a video on Tuesday appearing to show captured pilot Mouath al-Kasaesbeh being burnt alive in a cage. Jordan, which has participated in a U.S.-led military campaign to bomb Islamic State positions, responded overnight by executing two al Qaeda convicts on death row. Egypt's top Muslim authority, the 1,000 year old Al-Azhar university revered by Sunni Muslims around the world, issued a statement expressing "deep anger over the lowly terrorist act" by what it called a "Satanic, terrorist" group. The Grand Sheikh of Al-Azhar, Ahmed al-Tayeb, said the killers themselves deserved to be "killed, crucified or to have their limbs amputated." The Islamic State posted a religious edict on Twitter, which ruled that it is permissible in Islam to burn an infidel to death. However, senior clerics across the Islamic world argued that inflicting death by fire was always banned under Islam. "The Prophet, peace be upon him, advised against burning people with fire," Sheikh Hussein bin Shu'ayb, head of the religious affairs department in southern Yemen, told Reuters in Aden. Saudi cleric Salman al-Odah wrote on his Twitter account: "Burning is an abominable crime rejected by Islamic law regardless of its causes." "It is rejected whether it falls on an individual or a group or a people. Only God tortures by fire," he added.