NEW DELHI — Protests against India's controversial new citizenship law were expected to attract large crowds in major cities Thursday, one day after large gatherings were banned in key regions and parts of the capital in an attempt to clamp down on the demos.

The rallies against the law over the past few days have often turned violent, with six people killed in the northeastern state of Assam, where police have fired tear gas and arrested hundreds of people.

The law allowing New Delhi to grant citizenship to non-Muslim nationals from three neighbouring countries follows other policies from the government of Prime Minister Narendra Modi that critics say are designed to marginalise Muslims in the Hindu-majority nation.

Modi says the measure is meant to protect persecuted minorities, but critics see it as part of a master plan by him and his Bharatiya Janata Party (BJP) to define India as a Hindu nation and move away from its secular foundations.

Police refused a march permit for one of two major Thursday demonstrations in Delhi, officials said. Organisers said they planned to march anyway.

Delhi authorities on Wednesday even imposed a ban on gatherings of more than four people in some of the city's Muslim-dominated districts.

A crowd of mostly young people rallied outside Delhi's Jamia Millia Islamia University to protest the law, defying the ban on large gatherings.

"We are really very angry with the BJP government... They have taken racism to the extreme point," Taiba Hadis, 18, said at the rally.

"They are questioning our existence, and it is high time for us to speak up."

In the financial capital Mumbai, hundreds of people under tight security carried placards with the words "India is Ours" and chanted "We Are All One".

"We just cannot go along with this bill. I can't believe we now have to prove our citizenship after living in India for so many years," Tabeer Rizvi said as the Mumbai crowd burst into a Hindi version of the US civil rights movement anthem "We shall overcome".

"I am not surprised to see people of all religions come out to protest this bill."

Rallies were also held in other states including West Bengal, Tamil Nadu and Telangana.

There were sporadic clashes between police and demonstrators in some cities as well as small counter-protests.

The latest round of protests came as the Supreme Court rejected pleas for an immediate stay on the legislation, but deferred the case to January for extensive hearings.

Petitioners have said the legislation is unconstitutional and counter to India's cherished secular traditions. — AFP