GUWAHATI, India — Nearly 2 million people have been left off a list of citizens released on Saturday in India's northeastern state of Assam, after a mammoth years-long exercise to check illegal immigration that critics said targeted the region's Muslim minority.

Resentment against illegal immigrants has simmered for years in Assam, one of India's poorest states, with residents blaming outsiders, many said to come from neighboring Bangladesh, for stealing their jobs and land.

Critics accuse Prime Minister Narendra Modi’s ruling Hindu nationalist party of stoking the sentiment against illegal immigrants, and misusing the register to target even legal Muslim citizens.

His close aide, Home Minister Amit Shah, has previously vowed to weed out illegal immigrants, calling them "termites."

Officials checked documents submitted by roughly 33 million people for a draft released last year of a National Register of Citizens (NRC) in Assam, which left out more than 4 million residents of the state, many of them Hindu.

But the final list now includes 31.1 million people, with 1.9 million excluded, Prateek Hajela, the coordinator of the state's register, said in a statement.

"Any person who is not satisfied with the outcome of the claims and objections can file an appeal before the foreigners' tribunals," Hajela said, adding that everyone had been given an adequate opportunity to be heard.

Those excluded have 120 days to prove their citizenship at hundreds of regional quasi-judicial bodies known as foreigner’s tribunals. If ruled to be illegal immigrants there, they can appeal to higher courts.

To establish citizenship, people in Assam have had to furnish proof of residence in India going back decades, before March 24, 1971, the year in which hundreds of thousands of people fled Bangladesh, as it split off from Pakistan.

State officials say they do not know the eventual fate of those finally adjudged foreigners. Bangladesh has not committed to accepting them.

More than 1,000 people are being held in Assam’s six detention centers for illegal immigrants and the state government has said it seeks to set up more centers.

Earlier this summer India's Supreme Court criticized the government, saying thousands of people who had been declared foreigners over the years had disappeared. BIJU BORO / AFP - Getty Images

Human rights activists have criticized conditions at the centers, and lawyers and activists have outlined problems with the functioning of the foreigners' tribunals.

Modi's government fully backs the citizenship project in Assam, and has often vowed to roll out a similar plan nationwide.

But Modi's Bharatiya Janata Party (BJP), which also rules the state, has had to change tack in recent months, because a large number of Hindus figured on the previous list.

Separately, the BJP has been planning legislation to ease the way for non-Muslim minorities from neighboring countries to become citizens. Some party members have publicly assured Hindus left off the list India would give them refuge.

The registry comes less than a month after the Modi government unilaterally stripped Jammu and Kashmir, India's only Muslim-majority state, of special constitutional protections that gave it political autonomy and exclusive land rights.

Kashmiris fear that the Himalayan territory, which is also claimed by Pakistan, will lose its culture and demographics in a Hindu land-grab.