A huge influx of Indian security forces was ordered into the north-eastern state of Assam ahead of a national register of citizens that could leave millions stateless as the government defines who has the right to stay in the country. The National Register of Citizens policy aims to separate what the Narendra Modi administration deems as “genuine” Indian citizens, as opposed to “foreigners”, based on documents that prove people were resident in the state after the 1971 war with Pakistan that led to the creation of neighbouring Bangladesh. Authorities in Assam have brought in 17,000 additional security personnel with public gatherings banned in some areas and “cyber units” scanning social media, in case of violent protests. The policy is seen as being a measure to send millions of Muslims “home”, despite many living in Assam for generations. The state government has also built a number of detention camps, that have been compared to giant jails. The list of those passing the NCR is due to be published on Saturday morning, with several large detention centres built to house those “failing” the nationality test. Security personnel stand guard at a National Register of Citizens office ahead of the release of the register’s final draft in Guwahati Credit: BIJU BORO/AFP/Getty Images Assam, a state of 33 million, has long seen large migrations from other parts of south Asia, especially during British colonial rule and around the 1971 war, with critics of Mr Modi’s Bharatiya Janata Party (BJP), saying the process reflects its Hindu nationalist aims to expel Muslims. In January India’s parliament passed legislation that aims to grant citizenship to people who moved to India from Bangladesh, Pakistan and Afghanistan as recently as six years ago – but not if they are Muslim. The Home Minister, Amit Shah, has called for the expulsion of “termites” and said before the BJP’s re-election in May that it would “run a countrywide campaign to send back the infiltrators”. Only those who can demonstrate that they or their ancestors were in India before 1971 can be included in the NRC, but in a land where documents are often rendered obsolete or frequently forged, observers say it is a bureaucratic nightmare. Around 4 million people are expected to not make the list, despite many having been born in India. But tackling the arcane process is a challenge for many in a poor region where illiteracy is rife and many lack official papers.