RIYADH - Dozens of Saudis staged a rare protest on Monday against the detention of relatives held without trial for security offenses in a country that escaped last year's Arab Spring unrest but has faced criticism for its human rights record.

Up to 50 people, including eight women, stood quietly outside a prosecutor's office by the side of a Riyadh road watched by uniformed policemen sitting in three police cars.

Human rights groups have faulted Saudi Arabia for a near total lack of democracy and intolerance of dissent. Rights groups have also accused the government of using its campaign against Islamist militants to imprison political dissidents.