On Sunday, 543 Saudi women urged the clerics in the Muslim world to make efforts for the release of all political prisoners who are held in jails of the Al Saud regime without trial or a clear charge.
The women also pointed out in the letter that there are around 30,000 prisoners held in the Saudi jails.
The letter comes a few days after two people were killed in clashes between inmates supporting and opposing the Saudi regime at the al-Hayer prison on the outskirts of the capital, Riyadh, on July 14.
Since February 2011, protesters have held demonstrations on an almost regular basis in Saudi Arabia, mainly in the Qatif region and the town of Awamiyah in Eastern Province, primarily calling for the release of all political prisoners, freedom of expression and assembly, and an end to widespread discrimination.
However, the demonstrations have turned into protests against the Al Saud regime, especially since November 2011, when Saudi security forces killed five protesters and injured many others in Eastern Province.