Saudi Arabia's leaders rushed to assure the world they were in full control but crude prices jumped back over US$40 a barrel on Tuesday after a suspected al Qaeda attack on the kingdom's oil sector.

Twenty-two people were killed in the shooting and hostage-taking rampage at the weekend, the second major strike in a month on the Saudi oil industry.

Britain warned more attacks were probable in the kingdom, the world's biggest oil exporter.

"(Attacks) are clearly possible. I would go further than that and say they are probable," said Britain's ambassador to Saudi Arabia, Sherard Cowper-Coles, whose country is the second largest investor in Saudi Arabia behind the United States.

A Briton was among 19 foreigners killed in the attack in the eastern city of Khobar, which like other oil hubs in Saudi Arabia is home to a large Western workforce.

"These criminal acts by deviants will only strengthen our resolve to fight terrorism," said Saudi Arabia's King Fahd, as security forces stepped up efforts to crack down on Saudi-born Osama bin Laden's al Qaeda, which has vowed to topple him.

The king has been in poor health since a stroke in 1995 and his rare public statement seemed to signal the importance the royal family attached to showing it was on top of the situation.

Source: CD/Agencies