The Citizenship Amendment Act and the National Register of Citizens exercise planned by the Narendra Modi-led government “may affect the status of India’s large Muslim minority of roughly 200 million”, a report released by the United States Congress’ think tank, Congressional Research Service said.

The report released on December 18 said that this is the first time in independent India’s history that a religious criterion has been added to the country’s “naturalisation process”.

The Citizenship Amendment Act, approved by Parliament on December 11, grants citizenship to six religious minority groups from Pakistan, Afghanistan and Bangladesh, provided they have lived in India for six years. The cut-off date is December 31, 2014. It has been widely criticised and called discriminatory because it excludes Muslims.

The CRS prepares reports periodically on matters of domestic and global importance for the lawmakers to take informed decision. However, these are not considered as the official reports of the US Congress.

“Its key provisions – allowing immigrants of six religions from three countries a path to citizenship while excluding Muslims – may violate certain Articles of the Indian Constitution,” the two-page report said, referring to Articles 14 and 15.

“Proponents say that Muslims do not face persecution in Pakistan, Bangladesh, or Afghanistan, and that the CAA is constitutional because it addresses migrants rather than Indian citizens,” the report said. “Yet it is not clear why migrants from other neighbouring countries with state [or favoured] religions, such as Sri Lanka [where Buddhism is the official religion and Tamil Hindus face persecution] and Burma [where Buddhism enjoys primacy and Rohingya Muslims are persecuted], are excluded from a path to citizenship. In addition, oppressed Muslim minority communities such as Pakistan’s Ahmadis and Shias enjoy no protection under the CAA.”

The think tank’s report detailed the international responses against the amended citizenship law and the protests that have erupted in several parts of the country.

“The New Delhi government maintains that the NRC update is a fair and non-discriminatory process driven by the Supreme Court that does not impose a religious test or render any persons stateless,” CRS said. It added that the United Nations, the US Commission for International Religious Freedom, and other independent human rights groups have expressed concerns about citizenship register.

Protests against the Citizenship Amendment Act and the National Register of Citizens have engulfed India in the past two weeks. The protests saw peaceful marches as well as intense clashes between the police and the demonstrators. The overall toll across India rose to 25 on Thursday.