Shiite Muslim dignitaries in predominantly Sunni Saudi Arabia denounced on Wednesday the use of violence by authorities in dealing with protests in the mostly Shiite east of the country. A statement signed by 41 people criticised using the \"language of arms against peaceful demonstrations\" and called for a \"serious investigation\" into the violence, which has killed seven people since November. They also called for the \"liberation of political prisoners\" and a lifting of the ban on the construction of places of worship by Shiites, whom they said are marginalised and discriminated against. On Monday, an interior ministry official characterised as \"new terrorism\" recent troubles in the eastern province of Qatif, and said the authorities would \"confront it the same way they did\" with Al-Qaeda. He said those behind the incidents are a \"minority, that is being manipulated from abroad.\" The immediate trigger for the protest movement among Saudi Shiites was a Saudi-led military intervention in neighbouring Bahrain to help its Sunni rulers crush Shiite-led pro-democracy demonstrations last March. Activists say Saudi authorities have arrested nearly 500 people since the protests started. Many have been released but dozens remain in custody, among them human rights activist Fadel al-Munasif and writer Nazir al-Majid. In January, Saudi authorities published a list of 23 men wanted on suspicion of involvement in the disturbances. Later the same month, the interior ministry announced that security forces had arrested nine people suspected of involvement in the wounding of three policemen in Eastern Province. Most of Saudi Arabia\'s estimated two million Shiites live in the province, where the vast majority of the OPEC kingpin\'s huge oil reserves lie. They complain of marginalisation in the Sunni-dominated kingdom. Wednesday\'s statement blamed the unrest on the \"sense of desperation among the youth\" and warned that the situation could \"get out of control.\" Last week, Saudi police said they exchanged fire with \"masked gunmen\" at a protest in the east, killing one of them, in the second fatal clash in two days. Activists contacted by AFP from Dubai said that Zuhair al-Said, 21, was killed as security forces dispersed a protest on Friday against the death of another Shiite demonstrator the previous day. Prominent Shiite cleric Sheikh Hasan al-Saffar criticised the use of force against protesters saying: \"This will not solve the problem but will only further complicate it,\" in a speech published on a Shiite websites.