Beijing, Nov 25 (IANS): Millions of residents in Xinjiang region of China have been ordered to surrender their passports to the police, a move which rights groups said was taken to attack personal freedom.

The order came from the Shihezi Public Security Bureau Immigration Office in Xinjiang on October 19, which said that passports would be held by the police after an "annual check", the CNN reported.

Those wishing to travel abroad would have to seek permission from local authorities, and who refuse could be barred from leaving the country, it said.

Xinjiang is an ethnically divided and resource rich province that is home to around 10 million predominantly Muslim Uyghurs and around eight million Han Chinese.

No reason was given regarding the order, however, the World Uyghur Congress, a Germany-based rights group, said it was a deliberate move to restrict the movements of the Uyghur population.

"Although the regulations ostensibly target all residents, Chinese authorities in the past have taken clear steps to limit mobility rights for the Uyghur community in particular," the Congress said.

China has blamed Uyghur separatists for a number of attacks in recent years, including one on a coalmine in September last year, in which 50 people were killed.

Exiled groups and human rights activists said the government's repressive religious policies and economic marginalisation are provoking the unrest.

"Chinese authorities have given no credible reason for taking away people's passports, violating their right to freedom of movement," Sophie Richardson, China Director for Human Rights Watch, said in a statement.

"Doing so across an entire region is a form of collective punishment and fuels resentment toward the government in a region where tensions are high."