Al Qaeda branch in Syria, Al Nusra Front has published a book entitled "Islamic State: the Caliphate of Tyranny and Corruption" criticizing IS and warning militants against pledging allegiance to its leader, Abu Bakr Al Baghdadi. Al Nusra's media center described the book as the most important jihadi publication uncovering the truth on the IS 'infidels'. The book explains the reasons why IS has corrupted the concept of Jihad, describing its militants as "Khawarij" (deviated sect). Al Nusra closes the book by saying that the IS caliphate project is extremely dangerous and must be confronted. The book is considered to be the harshest criticism yet of IS by Al Nusra since the start of the dispute between the two extremist groups.
