East Turkestan: Uighurs still behind bars in China
The release of prominent Uighur businesswoman Rebiya Kadeer from prison in
China has been welcomed by rights groups.
But thousands of Uighurs have been detained for political reasons in recent years, and many are believed to still be in jail.
The BBC News website looks at three individuals whose cases have been highlighted by Amnesty International:
Tohti Tunyaz is a historian who was sentenced to 11 years in jail in March 1999 for "illegally acquiring state secrets" and "inciting separatism".
Mr Tunyaz, who was studying in Japan, was arrested in 1998 while on a trip to Xinjiang to gather material for his post-graduate thesis on Uighur history.
While there he had obtained a number of 50-year-old documents, which Chinese prosecutors described as state secrets.
He was also accused of publishing a book in Japan inciting separatism, but his Japanese professor has denied its existence.
Abdulghani Memetemin is a teacher and journalist who was sentenced on 24 June 2003 to nine years in jail for "providing state secrets for an organisation outside the country".
He was accused of helping an NGO based in Germany and run by exiled Uighurs, the East Turkestan Information Centre, with its work.
Specifically he was charged with sending ETIC news reports and transcriptions of speeches by Chinese officials and trying to recruit new reporters for the group.
Muhammed Tohti Metrozi
Muhammed Tohti Metrozi went missing in Rawalipindi, Pakistan, on 16 July 2003. An independence activist, he had fled there from Xinjiang where he had spent two months in detention on suspicion of separatist activity.
He was accepted as a refugee by the United Nations High Commissioner for Refugees and was awaiting resettlement to Sweden at the time of his disappearance. He has not been seen since he went to meet a Pakistani government official.
He is reported to have been returned to China, detained, and possibly tried, in connection with his activities to help Uighur refugees in Pakistan and his application for asylum.