The head of Sunni Islam's top university has called for the crucifixion of Islamic State militants over the burning of a Jordanian fighter pilot - an act even Al-Qaeda condemned as 'deviant'.

Responding to the murder of Moaz al-Kasasbeh, the Grand Sheikh of Al-Azhar university in Cairo, Ahmed al-Tayib, said those responsible must face 'killing, crucifixion and chopping of the limbs.'

His judgement came as a Twitter account linked to Al-Qaeda in the Arabian Peninsula, the Yemeni branch of the terror group, denounced the killing as 'conclusive proof of Isis' deviance'.

Gruesome: Moaz al-Kasasbeh stands inside the cage where he was burned to death, in a frame taken from the video circulated by Islamic State militants yesterday showing the killing of the Jordanian fighter pilot

Barbaric: An ISIS extremist lights a trail of petrol leading to the cage in which the 26-year-old stands

The so-called Islamic State showed the gruesome killing of Kasasbeh in a video on Tuesday. He was captured in Syria in December when his plane went down during a bombing mission.

Footage circulated online showed the 26-year-old locked in a cage, doused with fuel and torched. Jordan immediately executed two Islamic State-linked death row prisoners in revenge for the killing.

Muslim clerics widely condemned Kasasbeh's burning, saying such a form of killing was considered despicable by Islam, no matter the context.

The 1,000-year-old Al-Azhar university, which is revered by Sunni Muslims around the world, issued a statement expressing 'deep anger over the lowly terrorist act' by what it called a 'Satanic' group.

Grand Sheikh Tayib said the act 'requires the punishment mentioned in the Koran for these corrupt oppressors who fight against God and his prophet: killing, crucifixion or chopping of the limbs.'

In Qatar, the International Association of Muslim Scholars, headed by prominent cleric Youssef al-Qaradawi and linked to the Muslim Brotherhood that has influence across the region, called the burning of Kasasbeh a criminal act.

'The Association asserts that this extremist organisation does not represent Islam in any way and its actions always harm Islam,' it said.

Condemnation: Responding to Kasasbeh's murder, the Grand Sheikh of Al-Azhar university, pictured, in Cairo, Ahmed al-Tayib, said those responsible must face 'killing, crucifixion and chopping of the limbs'

An eye for an eye: Jordan executed two IS-linked prisoners including Sajida al-Rishawi (left) hours after militants released the video that showed Kasasbeh (right) being burned alive

Saudi cleric Salman al-Odah wrote on his Twitter account: 'Burning is an abominable crime rejected by Islamic law regardless of its causes.'

ISLAMIC STATE: THE EXTREMISTS TOO BRUTAL FOR AL-QAEDA Born as an offshoot of Al-Qaeda, Islamic State was cast out of the international terror network last year in response to its brutality. Ayman al-Zawahiri, al-Qaeda's chief, last February issued a statement dissociating his group from Islamic State, which it accused of 'forbidden bloodshed' directed at fellow fighters. He said: 'We weren't informed about its creation, nor counselled. Nor are we satisfied with it: rather we ordered it to stop... Nor is al–Qaeda responsible for its actions and behaviour.' Islamic State is the successor of the al-Qaeda affiliate set up in Iraq in 2004 by Abu Musab Zarqawi to attack US occupation forces and Shia targets. Zarqawi was, in fact, reprimanded for his sectarian violence by Osama bin Laden and Zawahiri, who feared Muslim opinion would be alienated from al-Qaeda - advice that Zarqawi ignored. After Zarqawi was killed in 2006, his successor, Abu Bakr al-Baghdadi, set up the Islamic State in Iraq (ISI) and continued his mentor's legacy of violence. It reemerged in 2011 as a jihadi fighting force in the civil war in Syria, now re-named as ISIS, and earned a reputation for its rampant and gruesome violence, including beheadings and amputations. Since then it has overrun vast swathes of both Iraq and Syria, massacring those it deems 'infidels' and controlling local Sunni populations with its brutal interpretation of Sharia law. Advertisement

'It is rejected whether it falls on an individual or a group or a people. Only God tortures by fire,' he added.

In reply, Islamic State posted its own 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.

And even Muslim leaders sympathetic to the jihadist cause said the act of burning a man alive and filming the killing would damage Islamic State, which controls swathes of Syria and Iraq.

Abu Sayaf, a Jordanian Salafist cleric who spent almost ten years in Jordanian prisons for militant activity, including a plot to attack U.S. troops, said: 'This weakens the popularity of Islamic State because we look at Islam as a religion of mercy and tolerance. Even in the heat of battle, a prisoner of war is given good treatment.'

'Even if the Islamic State says Moaz had bombed and burned and killed us, and we punished him in the way he did to us, we say, OK but why film the video in this shocking way?' Sayaf told Reuters.

'This method has turned society against them.'

SITE, a U.S.-based monitoring service, quoted Abdullah bin Muhammad al-Muhaysini, whom it described as a Saudi jihadi, as saying on Twitter it would have been better if Kasasbeh's captors had swapped him for 'Muslim captives'. The killing would make ordinary people sympathetic to Kasasbeh, he said.

Of course, admirers of Islamic State cheered the killing. In a Twitter message, a user called Suhaib said: 'To any pilot participating in the crusader coalition against the holy warriors - know that your plane might fall in the next mission. Sleep well!'

Inconsolable: Saif al-Kasasbeh (centre), the father of Jordanian pilot Moaz al-Kasasbeh, is seen at the headquarters of the family's tribe in the city of Karak today as he mourns the loss of his son

Clean cut: Jordanian officials have told the devastated family of the 26-year-old (pictured) that they believed the footage to be genuine and that the man branded a 'hero' in his homeland was dead

Many ordinary people across the Middle East expressed disgust.

'This a criminal, barbaric act which has no place in Islam or humanity. Islam bears no responsibility for them and their claim to be an Islamic State is ridiculous,' said Nawaf al-Dweik, 43, an engineer from Ramallah in the West Bank.

'There should be a joint Arab force to go in and destroy these killers and be rid of them once and for all,' he added.

'I have never heard of any group that claims to be Muslim and commits such atrocities,' said Shadi Abdel-Wahhab, a 22-year-old university student in Sanaa, Yemen's capital.

The video circulated yesterday, titled 'Healing the Believers' Chests', shows Kasasbeh in an orange jumpsuit doused in fuel, before militants set light to a trail of petrol leading up to the cage where he is held.