Hit Extremists with 'Iron Hand', Says Top Saudi Cleric

Muslim leaders must strike the enemies of Islam with "an iron hand," Saudi Arabia's top cleric said during Friday prayers, in apparent condemnation of the Islamic State jihadist group.

Grand Mufti Sheikh Abdul Aziz al-Sheikh's comments came after Saudi Arabia and four other Arab nations joined the United States in aerial bombardment of the IS militants in Syria.

Speaking to Muslims from around the world in an address during the annual hajj pilgrimage, the mufti called on fellow Islamic leaders to "hit with an iron hand the enemies of Islam."

The IS group has declared a "caliphate" straddling Syria and Iraq where they have committed a spate of atrocities including crucifixions and beheadings.

"Your religion is threatened. Your security is threatened," he thundered, according to the official Saudi Press Agency.

"These criminals carry out rapes, bloodshed and looting," he said, adding that "these vile crimes can be considered terrorism" and their perpetrators have nothing to do with Islam.

"They are tyrants," he said, warning of "their deviant ideology."

The mufti spoke from Nimrah Mosque at Mount Arafat in western Saudi Arabia, home to Islam's holiest sites.

Close to two million Muslims from around the world were gathered at Mount Arafat for a day of prayer at the peak of the annual hajj.

The comments were the mufti's latest criticism of the extremists.

In August, he urged Muslim youth not to be influenced by "calls for jihad ... on perverted principles," and he described al-Qaida and IS jihadists as "enemy number one" of Islam.

The kingdom is seeking to deter youths from becoming jihadists after Syria's conflict attracted hundreds of Saudis.

King Abdullah decreed in February jail terms of up to 20 years for citizens who travel to fight abroad.