Thousands of Muslims in Uzbekistan have been imprisoned for alleged "religious extremism" as part of a government crackdown on peaceful Muslims who practise their faith outside government-approved mosques, according to a rights group.

At least 12,800 people - including human rights defenders, independent journalists, and activists - have been jailed since 2002, the Initiative Group of Independent Human Rights Defenders said in an annual report released on Thursday.

At least 300 Muslims have been arrested and convicted in 2015 alone, it said.

The report is based on thousands of documents, first-hand reports from the group's activists throughout Uzbekistan, and interviews with families and former inmates collected since 2002, the group's head Surat Ikramov said.

"The figure could be a bit higher, but is in no way lower," he told Al Jazeera.

 People and Power - The Long Arm of the Dictator

The former Soviet nation of 31 million is ruled by President Islam Karimov, a former communist official who is known for his repressive and dictatorial policies.

The 77-year-old leader, who has been at the helm since before Uzbekistan broke away from Soviet Union in 1991, considers Muslim groups and political parties a major threat to his iron-fisted rule.

Most of the jailed people are abused, tortured, and have their prison terms extended for the slightest violation of rules, the report said.

Prohibited from praying

In some prisons, the jailed Muslims are prohibited from praying and reading the Koran and are forced to sing Uzbekistan's national anthem instead, said Ikramov, who escaped an attack by masked men in 2003.

The report said a conviction triggers a string of arrests, interrogations, and further convictions of family members, neighbours, friends and business partners.

Suspected Islamists are routinely extradited or kidnapped by Uzbek security agents from Russia and other ex-Soviet states - even though some changed their citizenship and asked for asylum, rights groups say.

Karimov's government tolerates no political opposition and cracks down on civil and human rights groups and independent media, the report said.

Massive arrests and convictions of Muslims began in the late 1990s after an alleged assassination attempt on Karimov, and intensified in 2005 after government troops killed hundreds of Muslim protesters in the eastern city of Andijan.

Western governments condemned the massacre, but Karimov did not take the criticism lightly. He expelled a strategic US airbase on the border with Afghanistan and renewed ties with Russia - a former "colonial oppressor" he had lambasted only months earlier.

Corrupt officials

Most of the Muslims arrested and convicted in the 2000s were labelled as members of the Islamic Movement of Uzbekistan, a banned group still active in Afghanistan and western Pakistan, and known for its cruelty. Others are alleged to belong to Hizb-ut Tahrir, a group that strives to restore a caliphate - but rejects violence.

In recent months, Uzbek authorities have started jailing alleged sympathisers or members of the Islamic State of Iraq and the Levant (ISIL), mostly labour migrants returning from Russia, Western Europe or Turkey.

Millions of Uzbeks have left their over-populated, arid nation in search of work.

Although hundreds of Uzbeks are believed to have joined ISIL in recent years, the persecution and jailing of alleged ISIL loyalists is just a new tag for Uzbekistan's law enforcement agencies, and corrupt officials to continue the repressions, analysts say.

"Fighting ISIL in Uzbekistan is not a fight with a mythical Islamist threat. It is often inspired by security agencies to fulfil a quota" Daniil Kislov - a Moscow-based researcher on Central Asia whose Ferghana.ru website is banned in Uzbekistan - told Al Jazeera.

"It could also be a revenge to business competitors or score-setting with dissenters," he said.

Sometimes, non-Muslims face jail for alleged links to Islamist groups.

On Wednesday, the trial of Aramais Avakian, an ethnic Armenian Christian farmer accused of ties to ISIL, started in the central Uzbek region of Jizzak, Radio Liberty/Radio Free Europe reported.

His family denied the accusations and said the trial followed a disagreement with a local official who wanted to take over Avakian's fish farm, the report said.

More than 70 years of officially atheist communist rule could not root out Islam in Uzbekistan, where centres of Muslim learning such as Bukhara had flourished for centuries.

Although Bolsheviks purged Muslim clergy and replaced an Arabic alphabet with a Cyrillic one, Uzbeks kept observing Muslim traditions and praying - often clandestinely.

Source: Al Jazeera