Saudi Arabia has arrested eight suspected militants linked to a recent wave of clashes that killed at least five policemen in and around the capital Riyadh.
An Interior Ministry statement said it would not name them or the role they played in the clashes for the sake of the investigation.
It also held back details on when or where they were arrested, but said police had seized a large quantity of money, weapons and explosives, including firebombs and pipebombs.
Saudi Arabia is battling a surge in militant violence believed to be linked to the al-Qaeda network. The kingdom is trying to crack down on militants since suicide bombings killed at least 50 people last year.
Last week, suspected militants killed five policemen and two neighbourhood patrol guards in clashes one security source described as some of the fiercest the kingdom has seen so far.
Police also discovered and defused three car bombs in Riyadh since Tuesday, which the Interior Ministry statement said involved more than four tonnes of explosives hidden beneath fruit crates.
On Thursday, the United States ordered nonessential diplomats out of Saudi Arabia and warned all Americans they should leave, citing fresh signals of possible attacks on US and Western interests. The British embassy also urged its citizens to be alert.
Last week, one of Saudi Arabia's most wanted al Qaeda militants, in a video carried on an Islamist website, called on Muslims to kill Americans everywhere and vowed attacks against Arab leaders allied to Washington.