The situation spiralled out of control on Tuesday after protesters threw stones at police holding them at a barricade.

In West Bengal state, protesters opposing the new laws hurled a homemade bomb injuring three officers.

The new Citizenship Amendment Act makes it easier for non-Muslims from neighbouring Afghanistan, Bangladesh and Pakistan to gain Indian citizenship.

Critics say it weakens India's secular foundations since it does not apply to Muslims and fear it is part of a Hindu nationalist plan to marginalise the country's own Muslims.

Despite days of violent demonstrations, Prime Minister Narendra Modi dug his heels in on Tuesday.

"Both my government and I are firm like a rock that we will not budge or go back on the citizenship protests," Home Minister Amit Shah told the Times Network.

In the clashes in Delhi's Seelampur area, police fired shots in the air and lobbed more than 60 rounds of tear gas at protesters, some with their faces covered, who threw bricks, stones and bottles at police.

About 10 people, including policemen, had been brought in into the Jag Pravesh Chandra Hospital with injuries, a hospital official said.

Local imam Mohammad Daud said the confrontation began as a protest against the new citizenship law.

"We should protest against it, and we will protest against it. Neither is this a fight against the police, or a Hindu-Muslim issue. We only have a problem with the government," Daud said.

There are growing questions about the stance of Modi's Hindu nationalist party towards India's 172 million Muslims, who make up 14 per cent of the population.

The citizenship law follows the revocation of the special status of the Muslim-majority Kashmir region and a court ruling allowing construction of a Hindu temple on the site of a mosque razed by Hindu zealots.

Pakistani Prime Minister Imran Khan says India's actions could drive Muslims from India and create a refugee crisis.

Australian Associated Press