As India on Monday excluded four million Assamese people from the new list of citizens, Dhaka said the issue is India’s internal matter.
The Indian move, reports AFP, sparked “fears of mass deportations of Muslims from the northeastern state” of India.
The news agency added that the new draft register of citizens includes only those able to prove they were in Assam before 1971, when millions fled Bangladesh's war of independence into the state, and their descendants.
"This is India's internal matter," an official of the foreign ministry told UNB on Monday without elaborating further.
India, according to the BBC, says the process is ‘to root out hordes of illegal Bangladeshi migrants’.
The BBC report also says the move has sparked fears of a witch-hunting against Assam's ethnic minorities.
Hundreds of thousands of people fled to neighbouring India after Bangladesh declared itself an independent country from Pakistan on 26 March 1971.
The Indian government considers those who arrived before the war as legitimate citizens.
AFP says: Indian prime minister Narendra Modi's Bharatiya Janata Party (BJP) won control of Assam in 2016 after promising to expel illegal immigrants from mainly Muslim Bangladesh and protect the rights of indigenous groups.
Assam, where one third of the population is Muslim, is the only Indian state to compile a register of citizens.
On 23 July, the Indian media quoted Bangladesh high commissioner to New Delhi Syed Muazzem Ali as mentioning that "As of now this is an internal matter."
While talking to reporters in Kolkata, the high commissioner said this issue has not been raised at the official level by the government of India with the Bangladesh government at any stage and mentioned that he will not interfere in an internal matter.
Muazzem Ali said the issue can become 'bilateral' only after the Indian government takes it up with the Bangladesh government.