Saudi Arabia said it foiled an al Qaeda-linked plot to attack oil facilities and military bases, arresting more than 170 suspects, including some trainee pilots preparing for suicide operations.
The Interior Ministry, in a statement read on state television, also said police seized weapons and more than 20 million riyals ($5.33 million) in cash, from seven armed cells.
"Some had begun training on the use of weapons, and some were sent to other countries to study aviation in preparation to use them to carry out terrorist operations inside the kingdom,"
the statement said.
"One of their main targets was to carry out suicide attacks against public figures and oil installations and to target military bases inside and outside (the country)," it added.
Saudi Arabia is the world's top oil exporter, supplying about 7 million barrels a day to world markets. It holds nearly a quarter of the world's oil reserves.
The ministry said the suspects had been "influenced by the deviant ideology," a reference used by Saudi officials to refer to al Qaeda, led by Saudi-born Osama bin Laden.
Most of the 19 al Qaeda militants who commandeered hijacked planes in the Sept. 11 attack on the United States were Saudis.
Islamist militants swearing allegiance to al Qaeda launched a violent campaign to topple the U.S.-allied Saudi monarchy in 2003, carrying out suicide bomb attacks on foreigners and government installations, including the oil industry.
"It is obvious that the deviant group is still trying to revive its criminal activities in the kingdom," Interior Ministry spokesman Mansour al-Turki said.
Training in "Restive Areas"
He said that a total of 172 suspects from seven cells have been arrested, mostly Saudis but including some foreigners, who had trained abroad.
"They are linked to foreign elements and had benefited from restive areas to recruit, plan and train (for attacks)," he added, in an apparent reference to Iraq, where up to 3,000 Saudi militants joined Iraqi insurgents to fight the U.S.-led forces.
The television showed police digging in desert areas and searching buildings, seizing weapons, including rocket-propelled grenades and automatic rifles, computers and bundldes of money.
Militants in February killed four French expatriates working and living in Saudi Arabia in the latest attack on foreigners in the pro-Western kingdom.
Saudi Arabia warned foreign embassies last month that a group blamed for the killings could strike again.
Al Qaeda militants have said they want to drive "infidel" Westerners out of Saudi Arabia, the birthplace of Islam and home to its holiest shrines.
Tough security measures and a powerful publicity campaign helped crush the violence but analysts and diplomats have said the underlying drives of radical Islamist ideology and anger at Western policy in the region remain strong.
Officials say about 144 foreigners and Saudis, including security forces, and 120 militants have died in attacks and clashes with police since May 2003, when al Qaeda suicide bombers hit three Western housing compounds in Riyadh.