The US military has returned 10 Saudi detainees from the Guantanamo Bay prison to their home country, a Pentagon spokesman said Friday. The transfer cuts the number of men now held at the isolated US Naval station in southeast Cuba to about 275, a decline of nearly a third in the last year. About 136 of the 759 people detained at Guantanamo since 2002 have been Saudi, the second-largest group after Afghans. The vast majority have been repatriated - despite the fact that more than 90 percent are still considered a terrorist threat. The US agreed to return the men with the understanding that Saudi Arabia will mitigate that risk, partly through a state program to reintegrate former detainees into civilian life, said Navy Cmdr. Jeffrey Gordon, a Defense Department spokesman.