Mumbai/Guwahati. A crackdown on illegal migrants in India's Assam state risks depriving millions of Muslim citizens and long-term refugees from Bangladesh of their right to live there, activists said.

Government officials say they are updating Assam's National Register of Citizens (NRC) for the first time in six decades to identify illegal Bangladeshi migrants who are overwhelming the state administration.

"Ostensibly, it is to identify foreigners but, in the process, they are targeting Muslims who are Indian citizens and refugees who have lived here for many years but have no proof," said Aman Wadud, a local rights lawyer.

"The state has made it very difficult for them, by limiting the type of documents they can submit as proof of citizenship."

Anti-migrant sentiment has long festered in Assam, home to tens of thousands of people from Bangladesh. Locals say the refugees threaten the state's culture and tradition and are cornering resources, including land.

State officials deny they are targeting Muslims and say they are following the terms of a 1985 accord between India and anti-immigrant protesters in Assam, which declares anyone who entered the state without documents after March 24, 1971 a foreigner.

"We are committed to having the NRC free from names of any illegal migrants," Assam's chief minister Sarbananda Sonowal told the Thomson Reuters Foundation.

"I am sure each and everyone would respect the NRC draft."

A draft list of all Indian citizens in Assam is due to be released by December 31.

Wadud said nearly five million Muslims, mostly married women, and Bangladeshi refugees who have lived in Assam for decades, risk being left off the register because officials will not recognize the proof of ancestry documents they have submitted.

Assam has refused to accept documents validated by village councils, after initially saying they were acceptable. These are often the only documents that rural Muslim women have, as they seldom have birth or school leaving certificates, Wadud said.

An appeal is pending before the Supreme Court to allow documents validated by village councils, he said.

"If names of genuine Indians are dropped from the NRC there would be total chaos in the state," said Abdul Khalek, a lawmaker in the opposition Congress party.

"We want the NRC to be fair."

Reuters