Indian authorities have left the names of almost 4 million people off a controversial registry list in the state of Assam, effectively  denying citizenship to mainly Muslims of Bengali origins.

The publication of the National Register of Citizens (NRC) on  comes amid popular anger over illegal migration into Assam, which shares a porous border with Bangladesh.
Proponents of the registry say it will help root out illegal Bangladeshi immigrants, but the move has prompted fears of possible deportation among Assam’s hundreds of thousands of Bengali-speaking Muslims.
The decision to impose a state-wide register of citizens has drawn parallels with Myanmar’s Rakhine State, where Rohingya Muslims have long faced persecution owing to their Bangladeshi ancestry.
Last year, hundreds of thousands of Rohingya were forced across the border into Bangladesh as part of a targeted attack labeled by the UN as ethnic cleansing.
Tensions over citizenship have been brewing for decades in Assam, resurfacing earlier this year with a government effort to rid the state of “Bengalis” and “foreigners.”
Many of the state’s Bengali community have lived in India for decades, crossing the border into Assam during the bloody Bangladesh (formerly East Pakistan) independence struggle in 1971.
Many others can trace their history back even further, arriving before the independence of India in 1947.

The All India United Democratic Front (AIUDF) General Secretary Aminul Islam said his party was shocked to see the number of people left off the list.

“It’s quite a huge number. We are shocked,” said Islam from the AIUDF party, which fights for the rights of people of Bengali origin in the state.

“There are several objections. The update process was being done under the supervision of the Supreme Court but it was unfortunate to see the intervention of the state government on several occasions. We will approach the court later,” Islam told Al Jazeera.

“But for the time being, we appeal to the people to maintain peace and harmony.”

Human rights activist Suhas Chakma dubbed the NRC list the “biggest exercise for disenfranchisement in human history”.