Al-Azhar, Egypt's leading Islamic institution, issued a ruling on Monday prohibiting Muslims from watching a video showing the beheading of 21 Egyptian Christians by militants affiliated with the Islamic State group in Libya. 

In a statement Al-Azhar also urged media not to publish the "crimes of the terrorists" in order not to fulfill the "sinister aim" of affecting the morale of the Muslims and giving a reason to spread Islamophobia and defame Islam worldwide . 

Al-Azhar also prohibited the spread of the videos showing the execution of the hostages by the Islamist militant group. 

On Sunday the Islamic State militant group released an extremely graphic video showing the beheading of 21 Egyptian Christians who were kidnpaped several weeks earlier while working in Libya, provoking official and public anger in Egypt.