Saudi Arabia has arrested 208 people from several terrorist cells for allegedly planning to attack oil installations in the world's largest oil exporting nation.

An Interior Ministry statement issued in Riyadh says that a cell of eight militants, led by what it calls unidentified foreigners, planned to attack an oil facility in the Eastern province. 

The statement says another 22 suspects were part of a group plotting to assassinate clerics and security officials.

The exact involvement of the scores of other suspects arrested is not immediately known.  But the report says the security sweep was carried out over the past few months in various parts of the kingdom.

Earlier, the al-Qaida branch vowed to attack oil installations in Saudi Arabia and in other countries that supply oil to the United States.

Suspected al-Qaida militants launched dramatic attacks against Westerners in Saudi Arabia in 2003.

 Some information for this report was provided by AFP, AP and Reuters.