Saudi authorities arrested 100 Shia protesters during demonstrations in the east of the country last week, a Saudi human rights group said today.
Hundreds attended protests in and around the region's main Shia centre, Qatif, calling for the release of prisoners and withdrawal of Saudi forces from Bahrain.
"During the peaceful protests last week in the Eastern Province, in the Shia populated areas of Safwa, Qatif and its villages and Alhassa 100 protesters were arrested," the Human Rights First Society said in an emailed statement today.
"Human Rights First Society is appalled by the reports that some of these 100 detainees were subjected to physical and psychological torture particularly in Alhassa."
Saudi Arabia, a US ally and the world's top oil exporter, has not see the kind of mass uprisings that have rocked the Arab world this year, but dissent is simmering as unrest spreads to neighbouring Yemen, Bahrain and Oman.
Saudi Arabia sent 1,000 troops to Bahrain, also led by a Sunni monarchy, last week to help contain pro-democracy protests led by majority Shia Muslims.
Interior Ministry spokesman Mansour al-Turki declined to comment on the report.
"Anybody who committed a violent act that is criminalised by law in Saudi Arabia will be arrested and anybody proved to be involved in calling for demonstrations will be arrested and sent to the court of law," Turki told Reuters.
Saudi Arabia's minority Shia complain of discrimination, saying they often struggle to get senior government jobs and benefits available to other citizens. The government of Saudi Arabia, an absolute monarchy that usually does not tolerate public dissent, denies the charges.
Almost no Saudis in major cities answered a Facebook call for protests on March 11, in the face of massive security presence around the country.
Dozens of Saudi men gathered outside the Interior Ministry in the capital Riyadh on Sunday, to demand the release of jailed relatives.
King Abdullah on Friday offered $93 billion in handouts and boosted his security and religious police forces but did not give any concessions on political rights.
Agencies