The Upper House of the Indian Parliament (Rajya Sabha) approved the Citizenship Amendment Bill on Wednesday with 125 votes in favour and 105 against.

This contentious bill, which had already cleared the lower house on Monday, will grant citizenship to persecuted immigrants of six non-Muslim communities from Pakistan, Afghanistan and Bangladesh. The bill amends the Citizenship Act, 1955, and will allow non-Muslims from the three countries, who entered India before December 31, 2014, to apply for Indian citizenship.

Protests erupted across the country with the religiously polarising bill set to be signed into law. People resisted curfews imposed in Guwahati on Thursday Morning to protest against the Citizenship Amendment Bill (CAB), with police opening fire to disperse the sheer volume of protesters. Army personnel were deployed at various north-eastern states including Tripura and Assam, where the situation remains very tense, to contain the turmoil caused by the passing of the CAB. Amid growing protests and hostility, India Prime Minister Narendra Modi quickly reassured the people of the state that the new law is not divisive by sending a series of tweets on Thursday.

He tweeted, “The Central Government and I are totally committed to constitutionally safeguard the political, linguistic, cultural and land rights of the Assamese people as per the spirit of Clause 6.”

“I want to assure my brothers and sisters of Assam that they have nothing to worry after the passing of #CAB. I want to assure them- no one can take away your rights, unique identity and beautiful culture. It will continue to flourish and grow,” he added.

Critics of the legislation have described the bill as deeply divisive and one that breaks India’s long-standing commitment to a secular democracy. Besides the ruling Hindu nationalist Bharatiya Janata Party (BJP), the votes of Tamil Nadu’s All India Anna Dravida Munnetra Kazhagam (AIADMK) and Odisha’s Biju Janata Dal (BJD) which were crucial in securing the legislation.

AIADMK had previously voiced their support for the refuge for Tamils from Sri Lanka and the move to support the CAB seems to be a U-turn for the party under their new leadership.

Actor Siddharth went on Twitter to express his frustration on the new leadership of the AIADMK. “Deeply ashamed that Edapadi Palanisamy represents my state and our people. Supporting the #CAB shows his true colours, his lack of integrity and his desperate need to remain powerful at any cost. You will all be held accountable. Enjoy your temp power till then. #IndiaRejectsCAB,” he tweeted.

Opponents of the bill have expressed major concerns that the bill will elevate Hindu nationalism across India whilst simultaneously ostracising minorities.

See more from Al Jazeera, BBC, and The Hindu.