RIYADH, Saudi Arabia — Saudi authorities arrested 701 suspected Al Qaeda-linked militants in 2008, some of whom planned a car bomb attack on an oil installation, the Interior Ministry said yesterday.

The kingdom has previously reported arrests of large numbers of militants, including those linked to Al Qaeda, but the figure released yesterday was the highest to date.

Al Qaeda has called for attacks against the Saudi government, criticizing its alliance with America and hoping to disrupt the flow of oil to the West. The group has also labeled the government un-Islamic, even though the kingdom follows a strict interpretation of Islam known as Wahhabism.

The State Department spokesman, Tom Casey, said the reports of the arrests were an indication “a lot more” needed to be done to combat terrorism worldwide.

“It’s just another indication that Al Qaeda and the terrorist groups out there remain, and remain a challenge, not only for the United States and for Saudi Arabia but for the broader region and, really, for the world,” Mr. Casey said.

The 701 militants from various countries were arrested in multiple waves, but 181 were later released because there was no proof linking them to the terror network, according to a ministry statement carried by the official Saudi Press Agency. The remaining 520 are still in custody, it added.

The ministry said police found money, weapons, and ammunition owned by the suspects, who had buried some of it in remote areas. The men from regions that included Africa and Asia were organized into various cells, whose leaders were based outside Saudi Arabia, the statement added.