Without identity papers, nearly 2 million Indians are at risk of losing their citizenship.

On August 31, the northeastern Indian state of Assam released the National Register of Citizens (NRC) list, in which more than 30 million people were named but nearly 2 million others were not named and faced the risk of becoming citizenless.

According to the newly released list, a total of 31.1 million people in the state are confirmed as Indian citizens, but 1.9 million people are not listed because they do not have valid identification documents. Most of them are believed to be Muslims.

Only those who can prove that they or their ancestors were in India before 1971 will be included in the NRC list.

People wait to have their documents checked in Assam. Source: Getty Images

But tracing the origins is difficult for many in this region with high illiteracy rates and no archives.

The Indian government has given 120 days for those who are not approved to file complaints. Illegal immigrants and those without recognized citizenship will be sent to detention centers and then deported to Bangladesh.

Bangladesh has not commented on accepting those deported by India.

Earlier, on August 30, Indian authorities mobilized tens of thousands of police and paramilitary forces to Assam to maintain security and order for the announcement of the list.

With a population of 33 million, Assam state has witnessed a massive influx of migrants from Bangladesh and other regions over the years.

Illegal immigration has brought with it many complications for the state government and even for the indigenous Assamese people, not least of which is ethnic and religious violence.

Hundreds of thousands of Bangladeshis fled to India during the war for independence in the early 1970s. Most of them settled in Assam state, nearly 270 km from the Bangladesh border.