Sixteen Saudis have been transferred from the US prison in Guantanamo Bay to Riyadh, and immediately detained by authorities, US and Saudi officials said.
At least 53 Saudi nationals remain incarcerated at the US military facility in Cuba, Major-General Mansour al-Turki told the official Saudi Press Agency.
He said a total of 77 Saudis have now been returned from Guantanamo.
A Pentagon statement said: "These detainees were determined to be eligible for transfer following a comprehensive series of review processes conducted at Guantanamo Bay."
Prince Nayef bin Abdul Aziz, the Saudi interior minister, on Monday expressed his satisfaction with the level of co-operation between his country and Washington.
SPA quoted him as saying King Abdullah, the Saudi ruler, is keen to free all detainees held at the controversial detention camp.
Saudi custody
The prisoners transferred on Monday were expected to remain in custody while authorities investigated whether they had links to armed groups, the report said.
Six groups of Saudis have returned from Guantanamo, the first in May 2006, and all have been detained on arrival.
Saudi Arabia has freed many of the 45 prisoners who were repatriated last year after they ended their terms in Saudi jails under a deal with Washington.
Saudi public anger over the treatment of Saudi detainees in Guantanamo has been high in the US-allied kingdom.
Three Saudis have died in Guantanamo prison, one in May and two the previous year, in what US officials have said were suicides.
Many Saudis do not believe that and think the detainees were abused - a claim the US denies.
The US began using the Guantanamo Bay Naval Base in January 2002 for people captured in Afghanistan and Pakistan who were suspected of having links to al-Qaida or the Taliban.
Many of prisoners been held for years and nearly all are being held without charge.
Most of the 19 suicide hijackers who carried out the attacks on US cities in 2001 were Saudis.
Washington has designated Guantanamo prisoners "enemy combatants", denying them the prisoner of war status that would guarantee them certain rights under international law.