A security source said one of the detainees figures on a list of 36 wanted terrorists released by Saudi authorities last June.
An interior ministry source said police discovered last week the suspects' hideout in a warehouse in Riyadh where they seized explosive materials, assault rifles and ammunitions, in addition to three cars.
He said communication equipment, cameras, a computer and video tapes as well as false car plates were also confiscated.
On March 29, the Saudi interior ministry announced the arrest of 40 suspects and the seizure of arms and ammunitions in the region of Abqaiq, where the foiled attempt on the oil facilities occurred last February.
The ministry then said in a statement that "the arrests were within the framework of official hunt for members of the misguided group," the expression commonly used by the Saudi authorities to designate al-Qaida.
Two policemen and two of the attackers were killed in the aborted attempt on Abqaiq's facilities. Soon after, the authorities said they killed five terrorists who took part in the attempt and captured a sixth.
On the list of 36 wanted terror suspects, 15 are operating inside Saudi Arabia, and 21 -- including 15 Saudi nationals -- are believed to be outside the country.
The oil-rich Muslim conservative kingdom has been rocked by a string of terrorist attacks since May 2003 in which 265 people have been killed, including civilians, security forces and gunmen.