Millions of residents in China's northwestern Xinjiang region have been ordered to surrender their passports to local police, reports CNN.
The order came from the Shihezi Public Security Bureau Immigration Office in Xinjiang on October 19, which said that passports would be held by police after an "annual check."
Residents wishing to travel abroad would have to seek permission from local authorities, the statement said. Those who refuse could be barred from leaving the country.
CNN notes that 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 for the policy, however the World Uyghur Congress, a Germany-based rights group, said it was 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 in a statement.