Saudi security forces arrested dozens of people this week during protests by families seeking freedom for relatives detained on security charges, activists and witnesses said.
Families of security detainees have regularly staged small protests in Riyadh and some other cities over the past two years in defiance of a government ban on demonstrations.
They accuse the government of holding their relatives without trial or failing to release them after they were found innocent or had completed their sentence.
The authorities have repeatedly denied those charges and earlier this year set up a website where relatives of detainees can track the progress of their cases. They say those being held are suspected Islamist militants.
Witnesses said police quickly surrounded around 100 mostly male protesters at a demonstration in the city of Buraidah in the central province of Qassim on Tuesday and made some arrests. Some of those detained were later released, the witnesses said.
A day earlier, women and children had staged similar protests in several Saudi cities to demand the release of jailed relatives but were also dispersed by police.
“Unlike others who are demanding a regime change, we were demonstrating peacefully for our rights,” said one witness who identified himself as Ibrahim, contrasting the protest with Arab Spring demonstrations in other countries.
“All we want is for our relatives to be freed or to be given a public and fair trial,” he told Reuters. Ibrahim added that he had a brother being held without trial.
A spokesman for police in Qassim Province could not be reached for comment.
After a protest earlier this year the authorities denied allegations by demonstrators that police had beaten them or torn off women’s veils.
Saudi security spokesman Major General Mansour Turki has previously said relatives of detainees are being manipulated by al Qaeda sympathisers trying to stir up trouble for the authorities.
Activists on Tuesday posted YouTube footage apparently taken using mobile telephones showing about 50 male protesters in Saudi national robes, most of them covering their faces with red headdresses, surrounded by baton-wielding security men.
The crowd, who also included some veiled women in black garb, began by chanting “There is no god but God and the unjust is an enemy of God” before switching to “peaceful, peaceful” as the security forces surrounded them. The authenticity of the recording could not immediately be verified.
Saudi Arabia says it has detained a total of 11,000 people on security grounds during the last decade but that only around 2,700 remain in custody. Saudi human rights activists have said they believe the real numbers are higher and that they include people detained only for demanding political change.
The Kingdom cracked down on Islamist militants after a series of al Qaeda attacks on government and Western targets from 2003 to 2005. The militants were crushed inside the Kingdom but some fled to Yemen where they set up a new wing of al Qaeda that swore to bring down the Saudi ruling family.
In April a leading conservative cleric, Sheikh Salman al-Awdah, wrote an open letter to the government calling for reforms and fair treatment of detainees.