BEIRUT, Lebanon — Brushing back pressure from Washington, Prince Mohammed bin Salman of Saudi Arabia escalated his crackdown on even the mildest forms of dissent with the arrests this week of at least eight intellectuals, journalists, activists and their family members, rights groups and a Saudi associate of the detainees said on Friday.
Among those held are two dual Saudi-American citizens and two women — one of them pregnant, according to the groups. Many of the detainees are suspected of having complained to Western journalists and rights groups about the treatment of the imprisoned women’s rights activists, according to a Saudi national briefed on the case who spoke on the condition of anonymity in order to discuss confidential information.
The arrests come as Prince Mohammed, the 33-year-old de facto ruler of the kingdom, is under intense scrutiny from the West over the killing last fall of the dissident Jamal Khashoggi, a Virginia resident and Washington Post columnist who was ambushed and dismembered by Saudi agents in Istanbul. American intelligence agencies have concluded that Prince Mohammed ordered the killing.
In the aftermath, a chorus of American lawmakers from both parties have publicly urged the crown prince to loosen his iron-fisted grip by releasing some of the nonviolent activists. Many lawmakers have focused attention on a small group jailed for campaigning for reforms to the kingdom’s austere social code — including the right for women to drive, which Prince Mohammed has granted.
Others have demanded the release of a dual Saudi-American citizen, Walid Fitaihi, a Harvard-trained doctor, who has been held without charges or trial for a year and a half.
Associates and relatives of the activists and Dr. Fitaihi have said that the detainees have been repeatedly tortured in prison.
The most recent arrests — the first high-profile detentions that Prince Mohammed has ordered since Mr. Khashoggi’s killing — suggest that the crown prince intends to continue his crackdown regardless of the American admonitions to reform.
Almost all those arrested in recent days are connected to a group of women’s rights activists who have been detained since last spring. They have been charged with acting as foreign agents and working to undermine the kingdom’s security, though rights groups say their detentions appear to stem from their activism.
Three of the women were granted temporary release last week, leading some observers to speculate that the international pressure on Saudi Arabia to improve its rights record was working. But the charges against them have not been dropped. There were also indications that several more detainees were to be released. But a week later, they remain in detention.
Those arrested this week had far lower profiles than the women’s rights activists and tended to be less outspoken, though they belonged to the same social and intellectual circles.
One of the dual American citizens detained, Salah al-Haider, is the son of a prominent activist temporarily freed last week, Aziza al-Yousef. He had publicly celebrated his mother’s return by posting photos of her on Twitter. The other is Bader el-Ibrahim, a Shiite author and physician who may have attracted the authorities’ attention because he has written about Shiites in Saudi Arabia. The kingdom’s population is mostly Sunni, and Shiites are often subject to discrimination.
Their names were confirmed by ALQST, a rights group based in London that has worked on behalf of the activists, and by a Saudi associate of the detainees who insisted on anonymity out of safety fears.
Most of the newly arrested are supporters or associates of the jailed women, said Yahya Assiri, the director of ALQST. He said he did not know what to make of the latest roundup, coming so soon after the authorities had allowed three of the women to go home.
“It’s just bizarre,” he said on Friday. “They released Aziza and they arrested her son. I couldn’t understand that.”
Neither the American Embassy in Riyadh, the Saudi capital, nor a spokesman for the Saudi Embassy in Washington responded to requests for comment on Friday.
Also among the group of recent detainees, according to Prisoners of Conscience, another rights group, was Yazed al-Faife, a journalist for a state-owned newspaper, Al Sharq. He had recently appeared in a video accusing Saudi officials of habitually neglecting parts of southern Saudi Arabia and suggesting that some officials’ dealings there had been corrupt.
Mr. al-Faife said that poverty, lack of opportunity and poor infrastructure along the Saudi border with Yemen had allowed Iranian intelligence to destabilize the area and incite discontent in the Saudi population there. This, too, may have been sensitive territory in the authorities’ eyes: Saudi Arabia, with its ally the United Arab Emirates, has drawn strong criticism globally for its destructive war in Yemen against the Houthis, a militant group believed to be propped up by Iran.
The latest detainees also include a couple, Thumar al-Marzouqi and Khadija al-Harbi, both writers. Ms. al-Harbi, who often writes on feminist themes, is pregnant, Mr. Assiri said. Others arrested included Mohammed al-Sadiq, Fahad Abalkhail and Abdullah al-Duhailan.
Mr. Assiri said ALQST believed, but had not yet confirmed, that at least two others had been arrested recently.
A ninth person, Anas al-Mazrou, a lecturer at King Saud University, is believed to have been detained last month. His arrest was most likely connected to his appearance on a human rights panel at a book fair in Riyadh, the Saudi capital, where he mentioned the imprisoned women’s rights activists.
The targeting of the women and their supporters is playing out the same time as another politically sensitive court case: the trial of 11 Saudi security agents and officials accused in Mr. Khashoggi’s killing.
Amid an international backlash over his death, the Saudi authorities are facing the delicate task of attempting to demonstrate that the kingdom is punishing those responsible without undermining the crown prince.