Alwaght- Saudi Arabia detained at least seven people, including two dual US-Saudi citizens, in yet another act of crackdown on supporters of women.
The 11 women on trial had campaigned for the right to drive and an end to the kingdom's male guardianship system. Their case has intensified criticism of Riyadh's rights record, already in the spotlight after last year's murder of journalist Jamal Khashoggi.
The US nationals are journalist Salah al-Haidar, whose mother Aziza al-Yousef is among those on trial, and Bader al-Ibrahim, a doctor and author of a book about Shia Muslim politics, London-based Saudi rights group ALQST said.
Those newly detained are not front-line activists but "writers and social media bloggers previously engaged in public discourse on reforms" the group said. They were detained late on Wednesday and Thursday, according to ALQST.
Five other people close to the women have also been placed under a travel ban since February, they added.
The Saudi government communications office and the US embassy in Riyadh did not immediately respond to requests for comment.
A Riyadh court last week temporarily released three of the women on trial, including Yousef, raising hopes of more lenient handling after months of lobbying by Western governments.
But the new detentions could signal that the authorities will resist international pressure and pursue harsh sentences.
Khashoggi's murder tarnished the reputation of Crown Prince Mohammed bin Salman(MBS), who courted Western support for his efforts to modernise Saudi Arabia. US and Turkish intelligence agencies believe Prince Mohammed ordered the killing, which Saudi officials deny.
Dozens of other activists, intellectuals and Muslim leaders have been arrested separately in the past two years in an apparent bid to stamp out the opposition.
The women on trial were arrested last May and branded as traitors. At least one of them has been charged under the kingdom's cybercrime law and faces up to five years in prison.
Five men arrested at the same time are not on trial. Rights groups say two of them have been released, but the others' status is unclear.
Another US-Saudi national, Walid al-Fitaihi, has been imprisoned since 2017 under Riyadh's anti-corruption campaign. His son told US senators last month he had been tortured in detention, with the tactics including electric shocks and whipping.
Some of the women activists have also alleged torture and sexual assault, which the authorities deny.
The siblings of one woman, Loujain al-Hathloul, who have publicised her case in US media, say men describing themselves as "close to the state" had asked her parents to stop them from speaking out.
"We stayed silent for eight months. We thought that being silent would solve the issue," her brother Walid al-Hathloul told CNN on Thursday.
"We found out at the end of the day that this made the case even worse and that's why we're speaking out now. At the end of the day we didn't have any options but to speak out."