Violent clashes have erupted in Delhi between police and hundreds of university students over the enactment of a new citizenship law that critics say undermines India's secular foundations.
The unrest has already led Japanese Prime Minister Shinzo Abe to cancel a planned visit to India on Sunday.
The new law offers a way to Indian citizenship for six minority religious groups from neighbouring Bangladesh, Pakistan and Afghanistan - including Hindus and Christians, but not Muslims.
Police fired tear gas and used baton charges to disperse scores of students demonstrating at Jamia Millia Islamia university in the heart of Delhi on Friday.
An official at the university dispensary said more than 100 students had been brought in with injuries but all had been discharged.
Critics of Prime Minister Narendra Modi's government say it is promoting a Hindu-first agenda for India and that the citizenship law excluding Muslims showed a deep-seated bias against India's 170 million Muslims.
Modi's ruling Bharatiya Janata Party says the new law is meant to help minority groups facing persecution in its three neighbouring Muslim countries.
The UN human rights office voiced concern that the new law is "fundamentally discriminatory in nature", and called for it to be reviewed.
Two people were killed in India's Assam state on Thursday when police opened fire on mobs torching buildings and attacking railway stations in protest at the new citizenship rules signed into law.
Abe cancelled a trip to Assam for a summit with his Indian counterpart Narendra Modi that had been due to begin on Sunday.
"With reference to the proposed visit of Japanese PM @AbeShinzo to India, both sides have decided to defer the visit to a mutually convenient date in the near future," Indian foreign ministry spokesman Raveesh Kumar said in a tweet.
Australian Associated Press