The Indian state of Assam was due Saturday to publish a highly contentious citizens' register that could potentially lead to several million people becoming stateless.
Most of those left off are expected to be Muslims, stoking fears among India's 170-million Islamic minority for their future under Hindu-nationalist Prime Minister Narendra Modi.
Assam in northeastern India, an impoverished isolated state of 33 million, has long seen large influxes from elsewhere, including under British colonial rule and around Bangladesh's 1971 war of independence when millions fled into India.
For decades this has made Assam a hotbed of inter-religious and ethnic tensions. Sporadic violence has included the 1983 massacre of around 2,000 people.
The has led to pressure from those who see themselves as genuine Assamese for a lasting solution -- which they hope will come from the National Register of Citizens (NRC) to be released on Saturday.
Only those who can demonstrate that they or their forebears were in India before 1971 can be included in the list.
But navigating the complex process is a huge challenge for many in a region of high illiteracy where many lack documentation.
A draft published last year saw around four million people left off. The final list is expected to exclude around two million, although estimates vary.
Members of Modi's Hindu nationalist Bharatiya Janata Party run Assam -- and critics say the NRC process reflects the BJP's goal to serve only its co-religionists.
In January India's lower house passed legislation that grants citizenship to people who moved to India from Bangladesh, Pakistan and Afghanistan as recently as six years ago -- as long as they are not Muslims.
Home minister Amit Shah, Modi's right-hand-man, has called for the ejection of "termites" and said before the BJP's thumping re-election victory in May that it would "run a countrywide campaign to send back the infiltrators".
Those left off the NRC will have 120 days to appeal at special Foreigners Tribunals, which the government says are being expanded in number.
But critics say that tribunal members can be underqualified and are subject to "performance" targets, and that the entire process has been riddled with inconsistencies and errors.
Camps and suicides
Those who have been rejected by the tribunals and have exhausted all other legal possibilities can be declared foreigners and -- in theory -- be placed in one of six detention centres.
Ten new such camps have been announced. One with space for 3,000 is being constructed in Goalpara, west of Assam's capital Guwuhati.
The camps currently hold 1,135 people, according to the state government, and have been operating for years.
Nur Mohammad, 65, spent almost 10 years in one such camp until a Supreme Court order saw him released this month.
"I just want to ask them what is my crime? I was born here and lived in Assam all my life," he told AFP. "I don't know if my name will be in the NRC or not."
Media reports say that there have been more than 40 cases of suicide caused by concern over the NRC.
Samujjal Bhattacharya from the All Assam Students' Union (AASU), a key driver behind the NRC, said the register was necessary to protect Assam's indigenous "sons of the soil".
"We are not ready to live here like a second-class citizens in our own motherland," he said.