Indian authorities stepped up security and shut down the internet in various places on Tuesday while members of the ruling party planned marches backing a new citizenship law even though nationwide protests against it are escalating.

An interior ministry official said the government expected all state security officials to be on duty on Christmas Eve and through the holiday week.

Read more: Violence flares at Delhi university as protests continue against Indian citizenship law

“We want the police to prevent an outbreak of violence but we also realise that the situation can get out of control, hence paramilitary forces will be deployed in markets and public spaces,” said a senior security official in New Delhi.

The Citizenship Amendment Act (CAA) aims to fast-track citizenship for persecuted Hindus, Parsis, Sikhs, Buddhists, Jains and Christians who arrived in India before December 31, 2014, from Afghanistan, Bangladesh and Pakistan.

Police also stopped opposition leaders Rahul Gandhi and Priyanka Gandhi of the Congress party from visiting Meerut city in the northern state of Uttar Pradesh (UP), where they meant to visit the families of the people who had died in the riots, Indian media reported today. According to NDTV, six people have died in Meerut in the protests.

According to NDTV, the Gandhis were told that there was a ban on large gatherings due to the security situation, after which the politicians left.

"We asked the police if they have any order, they didn't show us any order but they just said you can please go back," Rahul Gandhi was quoted as saying.

Police of UP — which has seen the most deaths in the protests — claimed that militants were stirring up the anti-CAA demonstrations.

“We have proof that a group with its headquarters in Delhi and its strongest base in the southern state in Kerala is behind the violence in the UP,” said senior police officer Kalanidhi Naithani.

In the last 10 days, UP police have taken nearly 900 people into custody for violence, said an official in the state's police control room. More than 2,000 people have been arrested across India.

At least 20 rallies in support or against the new law were scheduled in different cities with protesters from both sides canvassing on social media to get people out over Christmas and the New Year.

CAA's passing on December 11 triggered demonstrations in the eastern state of Assam, where protesters fear it will make illegal migrants from Bangladesh legal residents.

Elsewhere, critics say the law discriminates against Muslims and is part of Prime Minister Narendra Modi's Hindu nationalist agenda. The government denies that. Activists opposed to the law said they were trying to keep up the momentum and were looking for ways to work around the police clampdown and internet blackouts.

Senior members of Modi's Bharatiya Janata Party (BJP) leading rallies to support the law said they were determined to counter what they see as misleading criticism of it. "We want to explain that the law is not anti-Muslim and we want to expose that those who are leading the protests against the law are misleading innocent, uneducated Muslims," said BJP spokesman Gopal Krishna Agarwal.

At least 21 people have been killed since the law was passed in protests that represent the first major opposition to Modi's legislative agenda since his party's landslide re-election this year.

'Excessive force'

New York-based Human Rights Watch criticised the police action and called on them to stop using unnecessary lethal force against demonstrators.

The rights group said police had used excessive force against those protesting against the law, including many students.

“The authorities should prosecute violent protesters, but they also need to hold police officers to account for using excessive force,” said Meenakshi Ganguly, the group's South Asia director.

In Uttar Pradesh's capital of Lucknow, Tabassum Raza, a 26-year-old Muslim woman, said she was beaten by police who stormed into her home. “After barging into my house, one of the policemen immediately pointed a gun at my forehead and asked me to tell where were the men were hiding,” she said.

“When I told them there was no one in they started beating me with batons and damaged everything,” Raza said, showing bruised forearms and legs.

Vikash Chandra Tripathi, superintendent of police in West Lucknow, said the allegations were baseless and police were only searching for people involved in the violence. He said the police would investigate if an official complaint is lodged.

“So far the police have not received any complaints from anyone regarding,” he said.