As protests continue in Assam, New Delhi and other areas, Al Jazeera looks at three reasons why people are on streets.
The court on Wednesday asked the federal government to respond to a batch of petitions challenging the amendment to a 1955 citizenship law and said it will hear the case next on January 22.
Among the pleas the top court turned down was a petition seeking to stop the implementation of the new law, which lawyers said was based on religion.
The Citizenship Amendment Act (CAA) makes it easier for non-Muslims from the neighbouring countries of Afghanistan, Bangladesh and Pakistan who settled in India prior to 2015 to gain Indian citizenship.
Thousands of people have protested, saying the law is anti-Muslim and the latest in a series of measures by Prime Minister Narendra Modi‘s Hindu nationalist government to marginalise India’s 200 million Muslims.
“We want a stay order in the CAA case,” said Kapil Sibal, a lawyer for petitioners who challenged the law in court, adding it was in conflict with parts of the Indian constitution guaranteeing equality to all.
Supreme Court Chief Justice SA Bobde refused requests to hold off the implementation of the law, which came into effect last week.
Modi’s government says the law was intended to address the persecution of minorities such as Hindus, Sikhs and Christians in the Muslim-majority countries of Pakistan, Afghanistan and Bangladesh.
Those groups, many of whom have been languishing in India for years without rights, will now get an automatic path to Indian nationality if they came from these three countries before 2015.
But protesters say the exclusion of Muslims shows a deep-seated bias against the community, which makes up nearly 15 percent of India’s population, the third-largest Muslim population in the world.
Speaking to Al Jazeera, senior lawyer Colin Gonsalves said the law “clearly violates Article 14 of our constitution which speaks of equality for all people irrespective of religion”.
“The Citizenship Amendment Act leaves out 500,000 Muslims and allows regularisation of roughly three times that number of Hindus and other communities,” he said.
“Non-Muslims can come in, they can be regularised in India as citizens and Muslims similarly situated will probably be put in detention centres and incarcerated.”
The passage of the law last week follows a contentious citizenship registry process in northeast India’s Assam state intended to weed out people who entered the country illegally.
Nearly two million people in Assam were excluded from the list, about half Hindu and half Muslim, and have been asked to prove their citizenship or else be considered foreign.
So far, six people have died – four in police firing – in Assam during the protests against the new law, which residents fear will help Bengali-speaking foreigners to settle in the state.
On Wednesday, authorities tightened security restrictions, implementing a curfew in Assam, where continuing protests have disrupted daily life in the main city of Guwahati.
India is building a detention centre for some of the tens of thousands of people the courts are expected to ultimately determine may have entered without the required documents.
The new law also follows the revocation of the special status of the Muslim-majority Indian-administered Kashmir region, and a court ruling clearing the way for the construction of a Hindu temple on the site of a Mughal-era mosque razed by a Hindu mob in 1992.
University students across India have been leading a campaign to have the citizenship law overturned.
On Sunday, marches by students at New Delhi’s Jamia Millia Islamia University and Aligarh Muslim University in Uttar Pradesh state descended into chaos when police fired tear gas and beat unarmed protesters with wooden sticks. Dozens of students were injured.
Police say they acted with restraint. But the police response to the protests has drawn widespread condemnation and sparked a broader movement against the citizenship law.
Gonsalves was among a group of lawyers and activists who visited the injured students at the police station and in hospital.
“I saw this personally. I went to the police station and saw young people being brutally beaten and I saw in the hospital where they were full of bandages and broken legs,” he told Al Jazeera.
Demonstrations have erupted across the country, with thousands rallying in West Bengal, Tamil Nadu, Punjab, Maharashtra and Karnataka states on Tuesday.
Police fired shots in the air in a Muslim-dominated part of New Delhi to push back thousands of demonstrators throwing stones and glass bottles, demanding the law be withdrawn.
The demonstrators torched a police booth and several vehicles, forcing the police on Wednesday to restrict assembly in the Muslim neighbourhood.
More protests are planned for Wednesday in New Delhi and other cities.