By Kim Ghattas BBC News, Riyadh

A massive security operation is in force for the meeting

The campaign coincides with a counter-terrorism conference taking place in the Saudi capital, Riyadh.

Huge posters have been put up around the city and interviews have been broadcast with ex-militants talking about how they abandoned violence.

Saudi Arabia has witnessed a spate of bombings and shootings blamed on al-Qaeda linked militants since 2003.

The House of Saud is worried about the destabilising influence of militants linked to al-Qaeda.

People of the world, do you know the truth about Islam? Or do you think it is about bombing things and killing innocent people? Saudi public awareness jingle

The posters in Riyadh show the destruction in the wake of a suicide attack in the capital.

The slogan in large red letters reads: "Our religion condemns such acts."

Repentant militants talk on television about how happy they are to be on the right path again and a jingle on a programme about Islam asks:

"People of the world, do you know the truth about Islam? Or do you think it is about bombing things and killing innocent people?"

New message

The authorities here are trying to change the mind-set of their people now that they have realised terrorism is a threat not just abroad, but also to Saudi Arabia.

However, what Saudis are being told today about tolerance and respect for non-Muslims is often the opposite of what they have been taught their whole lives.

So it is difficult to tell what impact this campaign is having on the majority of Saudis, let alone hard-core extremists.

Terrorism experts say Saudi Arabia has made substantial progress in clamping down on militant networks.