Protests raged around the country despite the bans as opposition widened to the law, which excludes Muslims. The legislation has sparked anger at what many see as the government's push to bring India closer to a Hindu state.

Authorities erected road blocks and disrupted internet and phone services, including in parts of New Delhi, and tightened restrictions on protesters in the northeastern border state of Assam, which is where the protests began last week.

A curfew was imposed in parts of Mangalore, a city in southern Karnataka state, after police fired warning shots and used tear gas and batons to disperse a large group of protesters, the New Delhi Television news channel said.

Protesters also clashed with police in parts of Lucknow, the state capital of northern Uttar Pradesh state, where police said one person died from a gunshot fired by someone among the protesters. The protesters torched a bus, hurled rocks at police and damaged some police posts and vehicles, police said.

The new citizenship 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.

Critics say it's the latest effort by Prime Minister Narendra Modi's Hindu nationalist-led government to marginalize India's 200 million Muslims, and a violation of the country's secular constitution.

Modi has defended it as a humanitarian gesture.

Rather than contain uprisings, the protest bans appear to be helping them spread — from Assam and a handful of university campuses and Muslim enclaves in the capital — to campuses and cities from coast to coast.

"I think what is wonderful is that young people all in their 20s have so vividly understood the game plan, which is to divide people," said Zoya Hasan, a political scientist in New Delhi. "What people are saying is that you are going to divide, we are going to multiply."

The protests come amid an ongoing crackdown in Muslim-majority Kashmir, the restive Himalayan region stripped of its semi-autonomous status and demoted from a state into a federal territory last summer. They also follow a contentious process in Assam meant to weed out foreigners in the country illegally. Nearly 2 million people were excluded from an official list of citizens, about half Hindu and half Muslim, and have been asked to prove their citizenship or else be considered foreign.

India is also building a detention center for some of the tens of thousands of people the courts are expected to ultimately determine have entered illegally. Modi's interior minister, Amit Shah, has pledged to roll out the process nationwide.

Critics say the process is a thinly veiled plot to deport millions of Muslims.

The Modi government, which won a landslide re-election in May, had been able to push through those parts of its agenda without much opposition. That changed with the citizenship law.

"This may be a crack in the edifice"of the Modi government, said Nilanjan Mukhopadhyay, a political analyst and Modi biographer.

Some of the country's unwieldy and divided opposition parties have found common ground in condemning what they say has been a heavy-handed official response to the protests.

It's a good rallying point for the opposition because it is "a battle for liberal and democratic values," said Asaduddin Owaisi, a lawmaker and president of the All India Majlis-e-Ittehadul Muslimeen party.

Video on Thursday captured historian Ramchandra Guha, a biographer of independence leader Mohandas Gandhi, manhandled by police as he was detained in Bangalore, the capital of southern Karnataka state, where the government issued a ban on groups of more than four people gathering.

Guha told New Delhi TV on Thursday evening that police crammed him and hundreds of others who were detained into a wedding hall and let them leave later without explanation.

"As abruptly arrested, we were abruptly released," he said.

In New Delhi, Yogendra Yadav, a well-known political activist and the chief of the Swaraj India party, was among the more than 100 protesters detained at the city's iconic Red Fort and the surrounding historic district.

Protesters loaded into buses and jeeps shouted "down with Delhi police" as they were driven away.

Also worrying to protesters was the blocking of internet and phone services, a tactic authorities often use in Kashmir to try to prevent protests, but one rarely used in the capital.

"In this country we do not even have freedom to protest. It's very disappointing," said Upika Chahan, a social worker who took the day off work to protest at Red Fort.

Chahan, who is Sikh, said that while the citizenship law doesn't discriminate against her religious group, it doesn't augur well for India.

"If it's affecting one element of the ecosystem, sooner or later it's going to affect everyone in the ecosystem," she said.