China has imprisoned or detained at least 630 imams and other Muslim religious figures since 2014 in its crackdown in the Xinjiang region, according to new research by a Uyghur rights group.
The research, compiled by the Uyghur Human Rights Project and shared with the BBC, also found evidence that 18 clerics had died in detention or shortly after.
Many of the detained clerics faced broad charges like "propagating extremism", "gathering a crowd to disturb social order", and "inciting separatism".
According to testimony from relatives, the real crimes behind these charges are often things like preaching, convening prayer groups, or simply acting as an imam.
In total, the UHRP tracked the fates of 1,046 Muslim clerics — the vast majority of them Uyghurs — using court documents, family testimony and media reports from public and private databases.
While all 1,046 clerics were reportedly detained at some point, in many cases corroborating evidence was not available because of China's tight control over information in the region.
Among the 630 cases where it was, at least 304 of the clerics appeared to have been sent to prison, as opposed to the network of "re-education" camps most closely associated with China's mass detention of the Uyghurs.
Where information was available from court documents or testimony about the length of the prison sentence, the punishments reflect the harsh nature of Xinjiang justice: 96% sentenced to at least five years and 26% to 20 years or more, including 14 life sentences.
The database is by no means exhaustive — representing only a fraction of the total estimated number of imams in Xinjiang — and much of the data can't be independently verified. But the research shines a light on the specific targeting of religious figures in Xinjiang, appearing to support allegations that China is attempting to break the religious traditions of the Uyghurs and assimilate them into Han Chinese culture.
China denies those allegations, saying the purpose of its so-called "re-education" programme in Xinjiang is to stamp out extremism among the Uyghurs and other Muslim minorities.
The beginnings of 're-education'
Targeting of the Turkic ethnic groups in north-western China is not a new phenomenon. Muslim minorities suffered long periods of repression between the 1950s and 1970s, when Qurans were burned, mosques and cemeteries desecrated, and traditional dress and hair styles prohibited.
The 1980s brought a period of relative openness and revival. Damaged mosques were repaired and new mosques built; religious festivals allowed and imams and other figures permitted to travel; and the Quran translated for the first time into Uyghur, by the prominent Uyghur scholar Muhammad Salih Hajim.
But a violent uprising by Uyghur militants in 1990, in the town of Baren in Xinjiang, precipitated a crackdown by the Chinese state and the beginning of a two-decade period of gradually tightening control. Imams, seen by authorities as influential community figures, were increasingly required to demonstrate loyalty to the state.
In the early 2000s, many imams were compelled to attend formalised education courses that foreshadowed the mass "re-education" programmes pursued today against the general population. According to Human Rights Watch, roughly 16,000 imams and other religious figures underwent "political re-education" between 2001 and 2002.
Among them was Tursun, an imam who was first detained in 2001 for translating prayers from Arabic into Uyghur for his congregation, according to his niece.
Tursun's two-year stint in a "re-education through labour" camp marked the beginning of a two-decade ordeal at the hands of the state, his niece told the BBC from outside China. Her uncle was freed from the labour camp in 2002 but constantly harassed by police, she said, and frequently taken away again for two-week periods of "study". Then in 2005, he was detained again but this time sentenced to four years in prison.
"We were not given any notice from the court," his niece said. "My family went to the police station to enquire about his fate and the police gave them a handwritten note containing information about his prison sentence and the address of the prison."
Tursun was released from prison in 2009, only to be detained again in 2017 after the hardline politician Chen Quanguo was put in charge of Xinjiang and escalated the campaign against the Uyghurs.
As appears to be the case with other imams in the region, Tursun's family was subsequently targeted en masse, said his niece, who had left China by that time.
"After I heard the news of my uncle and his wife's arrests, I heard that my mother and many of my relatives were also arrested. Anyone over 14 was taken away," she said. "For the last four years I have been trying to find information regarding their whereabouts, especially my mother."