Students involved in a massive protest at a predominantly Muslim university in India’s capital have denounced the police response, as opposition grows to a new law that provides a path to citizenship for non-Muslim migrants.

A peaceful march by students from New Delhi’s Jamia Millia Islamia University at the weekend descended into chaos when demonstrators set three buses on fire.

Police responded with rubber bullets and tear gas. Video footage showed officers running after fleeing protesters and hitting them with wooden sticks.

“The 15th of December is a black day in the history of this country,” said human rights activist Farah Naqvi at a news conference.

The police response to Sunday’s protest has drawn widespread condemnation, and seems to have sparked an even broader movement against the Citizenship Amendment Act.

The new law applies to Hindus, Christians and other religious minorities who are in India illegally but can demonstrate religious persecution in Muslim-majority Bangladesh, Pakistan and Afghanistan. It does not apply to Muslims.

Prime Minister Narendra Modi’s ruling Hindu nationalist Bharatiya Janata Party has painted the new law as a humanitarian gesture, but critics say it is intended to help the party transform a multicultural and secular India into a distinctly Hindu state.

“This Act illustrates India’s centuries old culture of acceptance, harmony, compassion and brotherhood,” Mr Modi tweeted on Monday.

India citizenship protest
A bus in flames during a protest against the Citizenship Amendment Act in New Delhi, India, on Sunday (AP)

India is 80% Hindu and 14% Muslim, which means it has one of the largest Muslim communities of any country in the world.

“It is as if Indian citizens are rising to save the Indian constitution from the Indian state and the state policy,” said Ms Naqvi.

Students claim police lobbed teargas shells inside the campus, broke down the doors of the library and pulled out people to assault them. Dozens of students were taken to local hospitals for treatment.

Police have denied the charges and said they acted with restraint.