In reply to the outburst over the beheading of British aid worker Alan Henning, the Islamic State has released a five point explanation, especially meant for the Muslims to justify the brutal killing.

The five reasons aim to lay down an explanation based on Islamic principles to "guide the permissibility of killing the Prisoners."

Using views and opinions laid down by Islamic scholars, the ISIS statement tries to clarify to its followers that as per the Islamic dictates it has the right to behead or do what it wants with its prisoners.

The Sunni militant group that has taken control of several parts of Syria and Iraq wants to establish an Islamic State governed purely on principles of Sharia law.

The ISIS guide tells the "faithful" on how to reply to those who say that prisoners in Islam are not killed but rather shown compassion.

The first argument notes that all Mushrik (anyone who worship any other God other than Allah, which includes the Shias, Yazidis, the Kurds) can neither be granted amnesty nor be ransomed off. Quoting a passage from Surah Al-Anfal (The Spoils of War), it says: "Punish them severely in order to disperse those who are behind them, so that they may learn a lesson."

The second argument states the reason that a "kufaar" (including Jews and Christians) has to be killed is that if they are not killed, they will later return and pose a threat to Islam.

The third argument is that until and unless a prisoner says subhaanahu wa ta'ala, he can neither be shown generosity and freed without ransom nor be set free after paying a ransom.

The fourth is that amnesty and ransom are possible only after the killing of a large number. So if a captive was imprisoned after that, the Imam has a choice to kill him or (do) otherwise.

The fifth argument is that the Imam or someone acting on his behalf can choose between killing, amnesty, ransom or enslaving the prisoner.