"Zionism is behind terrorist actions in the kingdom," the Saudi Press Agency quoted Crown Prince Abdullah as telling a gathering of princes in Jiddah.

Zionism had misled "some of our sons," he said without elaborating.

Abdullah was speaking a day after four gunmen opened fire at an oil contractor's office in the industrial city of Yanbu, killing at least seven people - two Americans, two Britons, two Australians and a Saudi - and wounding 25 before leading police on a bloody chase, dragging the body of one victim behind their car.

Saudi Arabia's de facto ruler Crown Prince Abdullah said "Zionists' hands" were behind Saturday's attacks.

"Saudi Arabia is being targeted by Zionists...we are 95 percent sure that Zionists' hands were behind what happened," he said.

Saudi ambassador to Britain Prince Turki al-Faisal said that he thought al-Qaida was behind the attack, which killed two Americans, two Britons and an Australian.

"They are Saudis and they've joined a cult, al Qaeda, and are doing the bidding of the leader of that cult, Osama bin Laden," he told Sky News.

Meanwhile, Reuters reported that top Saudi al-Qaida leader Abdulaziz al-Muqrin has called for the bodies of Americans to be dragged through Saudi streets, urged fighters to expel "infidel" Americans from the birthplace of Islam and target security forces who stand in their way...