The Prisoners of Conscience Twitter account launched a campaign calling on Saudi Arabia to release detainees amid increased risk of an outbreak of the coronavirus.
The account said there is real danger to the prisoners' lives as a result of the poor conditions inside the prisons.
Scores of activists, families and relatives of detainees supported the campaign, including Lina Al-Hathloul, sister of detained human rights activist Loujain.
Al-Hathloul called for the release of all detainees, especially her sister, given the real danger posed by the spread of the coronavirus.
Activists have warned that there is a large group of elderly people in prison, who are extremely vulnerable to infection.
Saudi authorities said the number of coronavirus infections has reached 103.
As a precaution, authorities suspended all visits to prisons.