The seizures by security forces over the past six months also included more than 300 rocket-propelled grenades (RPGs) and launchers and more than 430 hand grenades, some locally made and others produced abroad, said a statement carried by the official SPA news agency on Monday.
The same statement carried "recorded remarks" of seven men described as "members of terror cells" about the circumstances of their involvement in terrorist activities.
The men were subsequently shown on state television making their remarks, although their faces were deliberately blurred.
Security forces also seized 120 weapons such as machine guns, other guns and automatic rifles, more than 352,300 rounds of ammunition and 674 detonators "for use in 350 bombings," it said.
Communications equipment, timers and equipment to set up truck bombs were also seized.
Security forces "were able to thwart many criminal terrorist operations that were in the last phases of planning," the statement said.
Saudi authorities arrested hundreds of suspected "extremists" in the wake of three simultaneous attacks on expatriate housing complexes in the Saudi capital on 12 May 2003 that killed 35 people, including eight Americans.
But bombers suspected of links with al-Qaida network struck again on 8 November, setting off a car bomb in another expatriate housing complex and killing 17 people, mostly Arabs.
The ministry statement also said security forces had detained "a large number" of people used as "terror tools," without giving specific numbers.