Nov. 28 (Bloomberg) -- Saudi Arabian authorities arrested 208 suspected militants who formed six different terror cells, one of which was planning to attack an oil facility, according to the government.

Officers thwarted an attack on an auxiliary oil facility in the east of the country, arresting eight members of that cell, the state-run Saudi Press Agency said on its Arabic-language Web site, citing the Interior Ministry. Another cell, with 18 members and led by a missile expert, was arrested on suspicion of plotting to smuggle eight rockets across a Saudi border, the agency said in its account.

``The fact that they were trying to use rockets, trying to smuggle missiles into the country, that's an indication that they're at the relatively advanced stage,'' said Nail al-Jubeir, a spokesman for the Saudi Embassy in Washington, in an interview late today. ``It is a major concern for us, and that's why we've been working closely with the neighbors to keep track of these guys.''

Saudi Arabia, the world's biggest oil exporter, is coordinating with neighboring countries and continuing to improve security in the energy industry, which has been a target for terrorist groups including al-Qaeda. Saudi forces in February thwarted a suicide attack at the Abqaiq oil-processing center, which handles two-thirds of the oil supply from the kingdom.

Protection Force

Earlier this month, Saudi Arabia said it was setting up a protection force of 35,000 men to guard oil fields, pipelines and crude processing plants. The government has trained about 9,000 men for the force, Interior Ministry spokesman General Mansur al-Turki said in a Nov. 20 interview.

In October 2002, a speedboat laden with explosives crippled a French oil tanker off the coast of Yemen to the south.

The 208 arrests in Saudi Arabia included 32 people detained for suspicious financial transactions at home and abroad and 16 others from an information cell who were being held in Medina. A cell of 22 members was arrested on suspicion that they were planning assassinations of scholars and security officials, according to the Interior Ministry.

Security forces arrested 112 people involved in coordinating the sending of foreign fighters to conflict areas, such as Afghanistan and Iraq.

U.S. State Department officials didn't have any immediate comment on the arrests, spokesman Rob McInturff said.

To contact the reporter on this story: Camilla Hall in London at chall24@bloomberg.net; Viola Gienger in Washington at vgienger@bloomberg.net

Last Updated: November 28, 2007 18:13 EST