The ministry said that the suspects were plotting to carry out suicide attacks on public figures and oil installations in addition to targeting military bases.

 

Top exporter

 

Saudi Arabia is the world's top oil exporter, supplying about seven million barrels a day to world markets. It holds nearly a quarter of the world's oil reserves.

   

The Saudi interior ministry said the suspects had been "influenced by the deviant ideology", a reference used by the kingdom's officials to refer to al-Qaeda.

   

Most of the 19 al-Qaeda fighters who commandeered hijacked planes in the September 11, 2001, attacks on the US were Saudis.

   

Muslim fighters linked to al-Qaeda launched a violent campaign to topple the Saudi monarchy in 2003, carrying out suicide bomb attacks on foreigners and government buildings, including the oil industry.

 

Scepticism

 

But one Western diplomat questioned the announcement, saying he doubted many of the men had played a key role in the plans.

 

The arrests come only four months after the authorities last announced the break-up of a major cell in December.
 
"It sounds like a small number of serious arrests, but with a lot of padding," he said, suggesting the government wanted to play up its anti-terrorism efforts.

 

"The specific nature of the targets could be pie in the sky."

 

Deviant group

 

Mansour al-Turki, an interior ministry spokesman, said: "It is obvious that the deviant group is still trying to revive its criminal activities in the kingdom."

 

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)," al-Turki said, in an apparent reference to Iraq, where up to 3,000 Saudi fighters are believed to have joined Iraqis in their fight against US-backed Iraqi government forces.

   

Television pictures showed police digging in desert areas and searching buildings, seizing weapons, including rocket-propelled grenades and automatic rifles, computers and bundles of money.