Saudi crown prince: 'Forces of darkness' tarnish Islam

Islam has been tarnished by "forces of darkness" and Saudi Arabia should do more to protect its youth from violent extremism, the kingdom's second crown prince said on Monday.

The comments by Crown Prince Moqren bin Abdul Aziz, in a speech for Saudi Arabia's 84th national day Tuesday, come after the kingdom this month agreed with other Arab states to back Washington against Islamic State (IS) militants in Iraq and Syria.

"Today, as Muslims, we are concerned because we have not done enough to protect our nation from extremism and its youths from militancy and extremism", Crown Prince Moqren said, quoted by the official Saudi Press Agency.

He added that some of the misled have replaced the doctrine of tolerance with "terrorism and bombing".

Officials and citizens must "join hands to deliver the true picture of Islam tarnished by the forces of darkness, and show our great religion with its ethics, knowledge and work in the face of deviant thoughts and interpretations," said the Crown Prince.

King Abdullah in March named Prince Moqren as a second heir, next in line after ailing Crown Prince Salman.

Saudi Arabia's Grand Mufti Sheikh Abdul Aziz al-Sheikh last month said Al-Qaeda and the IS group "have nothing to do with Islam and (their proponents) are the enemy number one of Islam".

The country is seeking to deter youths from becoming militants 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. 

Despite the order, in August the interior ministry said Saudi police arrested eight people in the northwest suspected of recruiting young people to join the IS group in Iraq and Syria.

Largely Sunni Saudi Arabia is home to Islam's holiest places, Mecca and Medina. The kingdom favours an austere form of Islam.