Indian students take part in a protest rally against a new citizenship law at Osmania University campus in Hyderabad, India. Picture: Mahesh Kumar A./AP

New Delhi - India's Supreme Court Wednesday said it would hear a clutch of petitions challenging a new citizenship law in January as protests against it spreads.

The petitions contend that the new law which makes it easier for non-Muslim migrants from Pakistan, Afghanistan and Bangladesh to become an Indian national goes against India's secular constitution by supporting religion-based discrimination.

There have been demonstrations across the country against the Citizenship Amendment Act which came into force on December 12.

A three-judge bench of the Supreme Court refused to stay operation of law and said it would take up the petitions in January, according to legal reporting website LiveLaw.

The court asked the federal government to file a response to the petitions by the second week of January, LiveLaw reported.

The more than three dozen petitioners include representatives of several opposition and regional political parties, lawmakers and legislators, Muslim groups, students organizations from north-eastern India, former bureaucrats and civil rights activists.

The petitioners argue that the new law violates the value of secularism upheld by the constitution by associating citizenship with religious identity.

Some question the eligibility of only of Hindus, Sikhs, Christians, Buddhists, Jains and Parsis facing religious persecution in three Muslim-majority countries and say persecuted Muslim groups like the Ahmadiyyas of Pakistan, Rohingyas in Myanmar as well as Tamils of Sri Lanka should be included.

Petitioners from north-eastern Assam state fear the law could legalise illegal immigrants who have entered the state from neighbouring Bangladesh. Four people have died in violent protests against the law in Assam.