Among them was Ayman al-Drees, the husband of a Saudi feminist activist Malak al-Shehri, who fled to the United States last year following the arrests of other women's rights activists. In 2016, Ms. al-Shehri herself was arrested after challenging the kingdom by tweeting a photo of herself wearing no headscarf or abaya, part of a protest against the conservative dress code that governs Saudi women.
She was later released, but on Friday her husband called her from his family's farm in Saudi Arabia to tell her that he had seen men approaching him, she said in a telephone interview on Friday from California.
al-Shehri said that her husband, who worked as an insurer, had muted his own activist post on Twitter two years ago, fearing to translate feminist videos from English into Arabic recently Awareness of feminist ideas spread to Saudi Arabia.
"We did not expect that because he did not do anything wrong. He did not do anything, "said Ms. al-Shehri in a broken voice. "He was careful, but it did not work."
She said she had urged him to go to the US, but he had refused, in part, because he did not believe he would be a target and partly because his income in Saudi Arabia was his wife supported.
According to Jäger of Conscience of Conscience, another group of rights, Yazed al-Faife, journalist of Al Sharq state newspaper, was among the youngest detainees. He had recently appeared in a video accusing Saudi officials of habitually neglecting parts of southern Saudi Arabia and suspected that the affairs of some officials there were corrupt.
Mr. Al-Faife said that poverty, lack of opportunities and poor infrastructure along the Saudi border with Yemen allowed Iran's intelligence service to destabilize the area and cause dissatisfaction in the local Saudi population. This, too, may have been a sensitive area in the eyes of the authorities: Saudi Arabia and its ally in the United Arab Emirates have voiced strong criticism worldwide of its destructive war in Yemen against the Houthis, a militant group allegedly supported by Iran.