Amnesty International has accused Saudi Arabia of reacting to the Arab Spring by launching a wave of repression. In a 73-page report published on Thursday, the human rights group said hundreds of people had been arrested, many of them without charge or trial. Prominent reformists had been given long sentences following trials Amnesty termed "grossly unfair". In the report, Amnesty accused the Saudi authorities of arresting hundreds of people for demanding political and social reforms or for calling for the release of relatives detained without charge or trial. So far unrest has largely been confined to the Shia minority in the east of the country. Saudi Arabia retorted by saying it arrested "only people involved in the riots, who were endangering the safety and lives of other citizens or policemen". In a statement released to the UK's The Guardian newspaper, it said: "The Kingdom of Saudi Arabia is committed to and respects human rights in accordance with Islamic Sharia, which is the foundation of our legal system. "The reality is that the Kingdom continues to be targeted by terrorists looking for finance and attempting to recruit Saudi Arabia's young citizens for terrorist operations within the kingdom and internationally. It is our responsibility to do everything we can to combat this evil." The report said that since February, when sporadic demonstrations began - in defiance of a permanent national ban on protests - the Saudi government carried out a crackdown that included the arrest of mainly Shia Muslims in the restive Eastern Province. Since March, more than 300 people who took part in peaceful protests in Qatif, Ahsa and Awwamiya in the east have been detained, Amnesty said. Most have been released, often after promising not to protest again. Many face travel bans. Last week 16 men, including nine prominent reformists, were given sentences ranging from five to 30 years in prison. Amnesty said they were blindfolded and handcuffed during their trial, while their lawyer was not allowed to enter the court for the first three sessions. "Peaceful protesters and supporters of political reform in the country have been targeted for arrest in an attempt to stamp out the kinds of call for reform that have echoed across the region," said Amnesty's Middle East and North Africa director, Philip Luther. "While the arguments used to justify this wide-ranging crackdown may be different, the abusive practices being employed by the Saudi Arabian government are worryingly similar to those which they have long used against people accused of terrorist offences," he said. Amnesty says that the government continues to detain thousands of people on terrorism-related grounds. Torture and other ill-treatment in detention are widespread, it says - an allegation Saudi Arabia has always denied. The BBC's Security correspondent Frank Gardner says Saudi Arabia has so far resisted the wave of change that has swept over much of the Arab world. The BBC correspondent said the kingdom's ageing monarch, King Abdullah, has reacted by releasing billions of dollars into the security and religious establishments, two of the pillars that support his ruling Al-Saud family. Amnesty has said the government drafted an anti-terror law that would effectively criminalise dissent as a "terrorist crime" and allow extended detention without charge or trial. Questioning the integrity of the King would carry a minimum prison sentence of 10 years, according to Amnesty.