Saudi Arabia's King Fahd vowed on Monday that his country would strike with an "iron fist" against suspected Islamic militants behind a bombing that killed at least 18 people in the capital Riyadh at the weekend.

The warning came as a senior U.S. official said the al Qaeda network was trying to topple the Saudi royal family and the pro-Western government of the world's biggest oil exporter.

A cabinet statement carried by the official Saudi Press Agency said the king told ministers that Riyadh would "strike with an iron fist whoever tries to violate the security of the country or its stability and the safety of its citizens and residents."

"(King Fahd) emphasized the will to confront terrorism and deal forcefully with such criminal and wicked acts and to get at criminals who commit such acts and whoever is behind them," the agency said.

Saudi-born Osama bin Laden's al Qaeda network is suspected of staging the suicide attack on Sunday that killed at least 18 people and wounded 120 in Riyadh. In May, a triple suicide bombing on a housing complex in Riyadh killed 35 people.

"It is quite clear to me that al Qaeda wants to take down the royal family and the government of Saudi Arabia," U.S. Deputy Secretary of State Richard Armitage told Al Arabiya television.

A witness said Saudi rescuers pulled one more body from the rubble on Monday, bringing the toll to 18 killed.

A compound resident said the two attackers used a car with military markings to get past a checkpoint outside the compound. When they reached the main entrance they shot a security guard and one other man, an Indian.

Armitage said Sunday's attack was shocking but noted Saudi security forces had gone on the offensive since May.

"So from our point of view, the authorities are working 24/7 to try to better the situation," he said, noting the difficulty was that the defenders must "be right 100 percent of the time and the terrorists only have to be right once."

Washington has been pressing Saudi Arabia to combat al Qaeda, believed responsible for the attacks on U.S. cities on September 11, 2001. Fifteen out of the 19 attackers were Saudis.

Saudi officials, along with Washington, blamed al Qaeda for the attacks in which bombers posed as police and blew up an explosives-rigged car in the Muhaya compound in Riyadh.

TIGHTER SECURITY

Security has been stepped up for diplomats and on Western residences in Riyadh. Many compounds for expatriates, who hold key jobs in the kingdom's oil industry and military programs, already resemble army camps from the outside.

Ringed by up to 50 soldiers from Saudi Arabia's national guard, the compounds' high perimeter walls are topped by razor wire, surrounded with concrete blocks and monitored by closed circuit television. Some have machine guns at the gate and armored vehicles covered by netting near the entrance.

Armitage, who arrived in Riyadh on Sunday, told reporters: "I can't say that last night's attack was the only or the last attack. My view is these al Qaeda terrorists -- and I believe it was al Qaeda -- would prefer to have many such events."

The blast came only days after Western nations issued fresh terror alerts and Washington shut its missions in the kingdom.

Western embassies in Saudi Arabia urged their nationals to remain vigilant after the attacks.

The U.S. embassy said in an advisory on Monday it and the consulates in the kingdom will remain closed to the public until further notice, pending further security assessment.

It however relaxed its restrictions on movement, saying its personnel and their dependants in Riyadh "are no longer confined to the diplomatic quarter and may move about Riyadh."

(China Daily November 11, 2003)