Over 120 Islamic scholars from around the world, many of them leading Muslim voices in their own countries, have issued an open letter denouncing Islamic State militants and refuting their religious arguments.
An array of Muslim leaders and groups have publicly rejected the Islamist movement since it imposed its brutal rule over large areas of Syria and Iraq this summer. Five Muslim nations have also joined a U.S.-led military campaign against it.
The 22-page letter, written in Arabic and heavy with quotes from the Quran and other Islamic sources, is just as clear as those groups in condemning the torture, murder and destruction Islamic State militants have committed in areas they control.
"You have misinterpreted Islam into a religion of harshness, brutality, torture and murder," the letter said. "This is a great wrong and an offense to Islam, to Muslims and to the entire world."
Its originality lies in its use of Islamic theological arguments to refute statements made by self-declared Caliph Abu Bakr al-Baghdadi and his spokesman Abu Muhammad al-Adnani to justify their actions and attract more recruits to their cause.
The letter is addressed to al-Baghdadi and "the fighters and followers of the self-declared 'Islamic State,'" but is also aimed at potential recruits and imams or others trying to dissuade young Muslims from going to join the fight.
Nihad Awad of the Council on American Islamic Relations (CAIR), which presented the letter in Washington on Wednesday, said he hoped potential fighters would read the document and see through the arguments of Islamic State recruiters.
"They have a twisted theology," he said in a video explaining the letter. "They have relied many times, to mobilize and recruit young people, on classic religious texts that have been misinterpreted and misunderstood."
The 126 signatories are all Sunni men from across the Muslim world, from Indonesia to Morocco and from other countries such as the United States, Britain, France and Belgium. Including Shi'ite or women signatories could have discredited the appeal in the eyes of the hardline Islamists it addresses.
Among those who signed were the current and former grand muftis of Egypt, Shawqi Allam and Ali Gomaa, former Bosnian grand mufti Mustafa Ceric, the Nigerian Sultan of Sokoto Muhammad Sa'ad Abubakar and Din Syamsuddin, head of the large Muhammadiyah organisation in Indonesia.
Eight scholars from Cairo's Al-Azhar University, the highest seat of Sunni learning, also put their names to the document.
In the letter, the scholars not only denounced the killing of U.S. journalists James Foley and Steven Sotloff and British aid worker David Haines as murder, but also rejected it based on the Muslim custom of protecting emissaries between groups.
The letter described as "heinous war crimes" several cases of militants killing prisoners, totalling at least 2,850. To stress this point in an Islamic way, it gave several quotes from the Prophet Mohammad forbidding such practices.
It said that Arab Christians and the Yazidis, followers of an ancient religion derived from Zoroastrianism, were both "people of the book" meant under Islamic sharia law to be protected. Both groups were driven to flight as Islamic State militants swept across northern Iraq.
"Reconsider your actions, desist from them, repent from them, cease harming others and return to the religion of mercy," the letter concluded.