Saudis have staged anti-regime demonstrations in the capital, Riyadh, and the eastern city of Qatif to express support for jailed female protesters.
The demonstrators called for the immediate release of a group of women who were arrested in the central city of Buraidah last week.
Activists say Saudi security forces arrested over 300 protesters, including scores of women and children, on March 1, after hundreds of Saudis gathered outside the investigation and prosecution bureau in Buraidah to demand the release of political prisoners.
Saudi authorities, however, claim that 161 people were arrested in connection with Buraidah protest and that they have so far freed some 100 of the detainees.
Protests against the ruling Al Saud dynasty have recently spread from the Eastern Province to other parts of the kingdom, with people of Buraidah threatening to stage a revolution against the regime.
In last week's protest in Buraidah, some protesters burned photographs of Interior Minister Prince Mohammed bin Nayef, who is King Abdullah's nephew.
Saudi activists say there are more than 30,000 political prisoners, mostly prisoners of conscience, in jails across the Kingdom.
According to the activists, most of the detained political thinkers are being held by the government without trial or legitimate charges and have been arrested for merely looking suspicious.