The day witnessed massive protest rallies, violence in parts of Uttar Pradesh and detention of hundreds of protesters.
Simultaneous protests raged in multiple cities across India on Thursday with huge crowds of students, activists and others defying prohibitory orders to voice their dissent against the newly amended Citizenship Act, resulting in violence and the killing of three protesters.
Two persons were killed in police firing on Thursday as protests turned violent in Mangaluru, police said.
Police sources said protesters attempted to lay siege to the Mangalore North police station and tried to attack police personnel, following which force was used to disperse them.
Another person was killed, allegedly due to firearm injuries, in Lucknow. However, it was not clear if he was killed in police firing.
Authorities barricaded roads and clamped down mobile services, including an unprecedented one in the national capital, while protesters also faced tear gas shelling and police batons at some places including in Uttar Pradesh where incidents of arson and stone-pelting gave the protests a violent colour.
Opposition parties also joined forces to attack the Narendra Modi-led government on the new law which they said goes against the "idea of India", even as the ruling Bharatiya Janata Party (BJP) asserted there would be no rethink on the implementation of the Citizenship (Amendment) Act and that the National Register of Citizens (NRC) would also be brought in.
Protests remained largely peaceful at most places with the agitators depending on slogans and placards to express their opposition to the new law and what they called 'barbaric police action' against students of Jamia Millia Islamia and Aligarh Muslim University. Some groups of protesters in Delhi also offered roses to policemen, saying love is their only answer even for tear gas shells and batons.
In the neighbouring Uttar Pradesh, where violent clashes saw at least a dozen vehicles, including bikes, being set afire, Uttar Pradesh Chief Minister Yogi Adityanath said those who damaged public property would have to pay for it and the culprits have been identified through video and CCTV footage.
"We will take revenge from them," Adityanath said.
There were incidents of stone-pelting and arson in Bihar as well, while rail and road traffic was hit in several states.
Barricades by police in and around the national capital, closing of Delhi Metro gates at 20 stations and an unprecedented suspension of mobile voice, messaging and Internet services in parts of Delhi added to woes of the public.
Left leaders including Sitaram Yechury, D Raja, Nilotpal Basu and Brinda Karat, activist Yogendra Yadav and historian Ramchandra Guha were among those who were detained in various parts of the country for taking part in the anti-citizenship law stir for defying prohibitory orders.
The law has been amended to enable the grant of speedier citizenship to non-Muslim refugees from Pakistan, Bangladesh and Afghanistan if they had to leave their respective countries due to religious persecution.
"India today has the ignominy of being the largest internet shutdown in the world. It is unacceptable. Metro stations were closed. This is worse than what we saw during the Emergency. The manner in which they are dealing with democratic protests is unacceptable," Yechuri said.
Section 144 of CrPc was imposed by Delhi Police in Red Fort area, but that did not deter scores of students and activists from converging there to raise their voice against the Citizenship (Amendment) Act and the police crackdown in JMI and AMU.
The agitators were put into buses in a bid to clear the Red Fort area. Holding placards and shouting slogans, the protesters allowed themselves to be escorted to the buses.
"We are requesting the protestors to please apply for the designated place for the protest. In the non-designated places, public face problems and many emergency services get affected," Deputy Commissioner of Police (Central) Mandeep Singh Randhawa said, while urging people to cooperate.
A large number of protesters converged near Sunehri Masjid in Old Delhi, after being pushed back by police from the historic Red Fort. They were heard raising slogans of 'Hum Honge Kamyaab', 'Inquilab Zindabad' filled the air.
Slogans of 'CAA Se Azaadi and NRC Se Azaadi' were also raised by the crowd, which included locals from Old Delhi and East Delhi and a large number of students.
A large number of protestors gathered at the Jantar Mantar as well.
Several companies in the NCR region also asked their employees to work from home and cautioned them against joining demonstrations.
Guha, who was detained in Bengaluru for defying prohibitory orders, said it was "absolutely undemocratic" that police were not allowing even a peaceful protest, which is the democratic right of citizens.
The Communist Party of India too staged demonstrations in Bengaluru against the citizenship law and the proposed nation-wide NRC.
Protests were also held at several other places in the state, including in Hubballi, Kalaburagi, Hassan, Mysuru and Ballary where police detained demonstrators who violated prohibitory orders.
In UP, while a state transport bus was set on fire in Sambhal area of the state, while violent protests broke out in capital Lucknow too when a mob pelted stones and torched vehicles parked outside a police post.
DGP O P Singh said police had to fire tear-gas shells to control the situation in Madeyganj area, while nearly 20 people have been taken into custody.
The opposition Samajwadi Party and Congress legislators held their protest at the legislative assembly complex in Lucknow.
AMU teachers held a silent march opposing the new law in Aligarh.
"We feel that we are fighting for the idea of India as envisaged by the founding fathers of the nation. This is not a struggle for the rights of any particular community," AMU Teachers Association secretary, Professor Najmul Islam said.
Hundreds of AMU students protesting against the amended Citizenship Act clashed with police on Sunday at a campus gate, leaving 60 injured. After the protest, the administration had announced the closure of the university till January 5.
In Bihar, members of Left-wing student organisations squatted on railway tracks at Rajendra Nagar Terminus early in the morning, while hundreds of activists of Jan Adhikar Party (JAP), floated by controversial ex-MP Pappu Yadav, burnt tyres on an adjacent road.
In Jehanabad, which had been a stronghold of the ultra-Left movement in Bihar, CPI(ML) activists disrupted traffic on national highways.
In Maharashtra, the Congress, NCP and various other parties came together under a front called 'Hum Bharat Ke Log' for a protest rally at Mumbai's August Kranti Maidan, the place where, in 1942, Mahatma Gandhi told the then British rulers to quit India.
Noted freedom fighter G G Parikh, 94, who participated in the Quit India movement in 1942, was present at the Maidan.
"The Constitution, drafted by Dr B R Ambedkar, is being violated and is under attack. This is the reason that the entire country has chosen this day to condemn the unconstitutional and divisive laws of the BJP government," the front said.
The rally saw thousands of people, including workers of political parties, students, professionals and also a smattering of Bollywood personalities, who made a strong case against the Act and the NRC. However, Maharashtra's ruling alliance partner Shiv Sena kept itself out of the rally.
Protests in West Bengal, Assam and Meghalaya, which were at the centre of the stir initially, were largely peaceful. Protests were also held in Telangana, Kerala, Tamil Nadu, Chandigarh, Jammu, Rajasthan and Madhya Pradesh, among other states.
At a rally in Kolkata, Chief Minister Mamata Banerjee dared the Modi government to go for a UN-monitored referendum over the amended law and the proposed nationwide NRC and said the BJP will have to quit if it fails such a "mass vote".
Two persons were arrested for hurling crude bombs on a group of anti-CAA protesters in West Bengal's North Dinajpur district, police said.
At some places, including in the national capital and Mumbai, pro-CAA demonstrations were also held by some groups.
(With PTI Inputs)