( CNN ) -- Amnesty International is urging Saudi Arabia to stop the `` outrageous restriction '' of peaceful protests , a call that comes after a crackdown last week on protesters in the country 's Shiite region . About 24 protesters were detained in the eastern city of Qatif last week as they denounced `` the prolonged detention '' of nine Shiite prisoners held without trial for more than 14 years , the human rights group said . Police kicked and used batons to beat three protesters in what was an apparent peaceful demonstration , Amnesty said in a statement dated Monday . `` The Saudi Arabian authorities have a duty to ensure freedom of assembly and are obliged under international law to allow peaceful protests to take place , '' said Philip Luther , deputy director of the human rights group 's Middle East and North Africa program . '' `` They must act immediately to end this outrageous restriction on the right to legitimate protest . '' There was no immediate reaction from the Saudi government to the Amnesty statement . The protests in the majority Sunni kingdom occurred Thursday and Friday , and they 've accompanied the calls across the Arab world for more freedom and democracy . Rights activists have been urging the right to protest for months in the kingdom , which prohibits all kinds of public demonstrations , and they have been denied permission to assemble . Lately , grass-roots ferment mirroring the unrest across the Middle East and North Africa has emerged , with a Facebook group calling for days of rage and Shiites taking to the streets . Activists have been calling for reform and the release of people jailed without charge or trial . Saudi Arabia 's Interior Ministry warned Saturday that its security forces will be `` authorized to take all measures against anyone who tries to break the law and cause disorder , '' the ministry said , according to the country 's state-run news agency . Amnesty said the recent detentions came a week after a prominent Shiite cleric , Sheikh Tawfiq Jaber Ibrahim al-'Amr was arrested after a sermon calling for reforms in Saudi Arabia . He was released without charge Sunday . Most of the protesters are believed to be held in a police station in Dhahran , an eastern city . Among them are activists who have protested arrests and discrimination against the minority Shiites . `` The Saudi authorities must investigate reports of beatings of protesters by security forces . They should also ensure that those detained are either charged with recognizable offences and tried fairly or released , '' Luther said . `` While in detention they must be protected from torture and other ill-treatment and given regular access to their family , lawyers and medical staff . '' The Shiite activists in `` prolonged detention '' have been held in connection with the deadly 1996 bombing of a U.S. military complex in Khobar in which 20 people were killed and hundreds injured . `` According to reports , they were interrogated , tortured and denied access to lawyers together with the opportunity to challenge the legality of their detention , '' Amnesty said .
Amnesty International decries `` outrageous restriction '' of peaceful protests . Protesters were detained last week . `` Prolonged detention '' without trial denounced .