Fresh protests rocked India on Monday as anger grew over new citizenship legislation slammed as anti-Muslim, after six people died in the northeast and as many as 200 were injured in New Delhi.
The law fast-tracks citizenship for non-Muslims from three neighbouring countries -- Afghanistan, Bangladesh and Pakistan.
Critics say it is part of Prime Minister Narendra Modi's Hindu nationalist agenda to marginalise the 200-million strong Islamic minority.
Modi denies this, tweeting Monday that the new law "does not affect any citizen of India of any religion", while accusing "vested interest groups" of stoking the "deeply distressing" unrest.
The former chief of the opposition Congress party, Rahul Gandhi, tweeted that the law and a mooted nationwide register of citizens also seen as anti-Muslim were "weapons of mass polarisation unleashed by fascists".
Human Rights Watch called for police across the nation to show restraint, amid claims that authorities were using unnecessary or excessive force to quell the unrest in several cities.
"The Indian government should address the concerns raised about the citizenship law instead of trying to shut down the protests with excessive force," HRW's South Asia director Meenakshi Ganguly said in a statement.
The UN human rights office said last week it was concerned the law "would appear to undermine the commitment to equality before the law enshrined in India's constitution", while Washington and the European Union have also expressed unease.
On Monday, fresh protests took place in multiple cities including New Delhi, Chennai, Bangalore and Lucknow, where hundreds of students tried to storm a police station.
The northeast, where allowing citizenship for any foreign migrants is opposed by many locals and which in recent days has been the epicentre of protests with six people dead, also saw fresh demonstrations.
Even so, the chief minister's office said late Monday that a curfew in four districts of the northeastern state of Assam would be lifted completely at 6:00 am on Tuesday.
Broadband internet would also be restored on Tuesday, officials said, but there was no mention of whether mobile internet, which has been blocked for several days, would be reinstated.
Ten people remain in hospital with gunshot wounds, while 190 people have been detained.
In the east in Kolkata, capital of West Bengal state, more than 10,000 people hit the streets Monday for a march led by state premier Mamata Banerjee, a firebrand Modi opponent.
Banerjee told the crowd that the law would be implemented in her state "over my dead body," Indian media reported.
State police said they fired tear gas to disperse hundreds of protesters elsewhere after they threw stones. More than 350 people were detained.
- Buses torched -
No major incidents were reported nationwide by Monday evening, although several metro stations were closed in Delhi as demonstrations there continued for a second day.
Late Sunday, rioters torched vehicles and police with batons fired tear gas and charged protesting students before storming Delhi's Jamia Millia Islamia university.
The university's vice-chancellor Najma Akhtar said Monday that 200 people were injured but police put the number at 39 students hurt with 30 officers also injured, one of them critically.
Police spokesman MS Randhawa said four buses, 100 private vehicles and 10 police bikes were damaged, and that officers exercised "maximum restraint, minimum force" despite being "provoked".
He denied some media reports that police opened fire. News channel NDTV reported that two people were in hospital with gunshot wounds.
Late Monday, about 100 young protesters remained on the streets, braving the freezing winter at the landmark India Gate to read the preamble of the constitution and show solidarity with the students.
The clashes also prompted university students to demonstrate elsewhere, including in the southern state of Tamil Nadu and in Bangalore.
"I want to make it clear -- nobody is scared. Like people in Hong Kong are protesting, in Chile they are protesting, and they are not scared," student Bhumika Saraswati told AFP in the capital.
Fellow student Shree Kumar said that the citizenship law was "against the Muslims... It's against the secular ideas of India."
Authorities in Uttar Pradesh state cut internet access in some parts following clashes between demonstrators and police in Aligarh on Sunday that saw 21 people arrested, authorities said.
Modi has said Muslims from Pakistan, Bangladesh and Afghanistan are not covered by the law because they have no need of India's protection.