Muslims pray under police watch in New Delhi.

Islamabad: Muslims in India's capital held Friday prayers under the watch of riot police, capping a week which saw 42 killed and hundreds injured during the city's worst bloodletting in decades.

Scores of mosques in New Delhi's northeast held their first sermons since mobs armed with swords, guns and acid razed parts of the district on Monday.

The violence was triggered by protests against a citizenship law seen by as anti-Muslim and part of Prime Minister Narendra Modi's Hindu nationalist agenda.

Paramilitary police patrolled the streets outside, still littered with broken shards of glass, stones and other debris.

Article continues after ad

Dozens of volunteers stood outside the main mosque in the neighbourhood of Mustafabad, home to some of the week's worst violence, urging devotees to disperse immediately after prayers.

"These are testing times. We have to be patient," said the imam, after calling on his congregation to stay calm.

Fear and tension were rampant through the neighbourhood, with police barring Muslim worshippers from what was left of one of several mosques set ablaze by Hindu rioters on Monday.

Nearby, a group of residents in the Hindu-dominated Shiv Vihar area blocked the lane leading to one of the local mosques with the burnt-out frames of motorcycles.

"We don't want violence," said Saleem Mirza, as police told Muslims to disperse to avoid any fresh trouble.

"We want to live in peace, work for our children and live a normal life. We prayed for peace for everyone today."

India's new citizenship law has triggered months of demonstrations between anti-government demonstrators and police. At least 30 people died in protests last year, mainly in Uttar Pradesh.

Many of the country's 200 million-strong Muslim minority fear the law -- combined with a mooted citizens' register -- will leave them stateless.

Modi has sought to allay the fears, but in recent weeks politicians from the prime minister's right-wing party have called the...