New Delhi: Guwahati, the epicentre of protests against the Citizenship Amendment Bill (CAB), was placed under indefinite curfew on Wednesday. The Army was deployed in the city and Assam Rifles personnel were deployed in Tripura as the two northeastern states plunged into chaos over the hugely emotive legislation.

Curfew was also imposed in Assam's Dibrugarh district on Wednesday night till further orders, news agency ANI reported. Dibrugarh Deputy Commissioner Pallav Gopal Jha said stones were pelted at the house of Chief Minister Sarbananda Sonowal in Lakhinagar area. The anti-CAB protesters also vandalised the houses of BJP MLA Prasanta Phukan and party leader Subhash Dutta, officials said.

The contentious legislation was cleared in the Rajya Sabha on Wednesday.

Army Public Relations Officer (PRO) Lieutenant Colonel P Khongsai said two Army columns have been deployed in Guwahati and are carrying out flag marches. Reports from Tinsukia said the Army has been deployed in the district and is carrying out flag marches there too.

A defence spokesperson had earlier said in a statement in Shillong that two columns of the Army were deployed in Tripura. The spokesperson later clarified that troops of the Assam Rifles, a paramilitary force commanded by Army officials, were pressed into service in Tripura.

The Army headquarters is closely monitoring the situation in the northeast, official sources said.

Internet services have been suspended in 10 districts of Assam, beginning 7 pm on Wednesday, as massive protests raged across cities, to prevent "misuse" of social media to disturb peace and tranquility and maintain law and order.

Services were suspended in Lakhimpur, Dhemaji, Tinsukia, Dibrugarh, Charaideo, Sivasagar, Jorhat, Golaghat, Kamrup (Metro) and Kamrup, a notification issued by Additional Chief Secretary (Home and Political Department) Kumar Sanjay Krishna, said.

Internet services are already suspended in Tripura for 48 hours from 2 pm on Tuesday to thwart attempts by mischief-mongers to disturb peace. An order issued by the Tripura government also prohibits SMSes on the networks of all mobile service providers.

Assam police chief Bhaskar Jyoti Mahanta initially said that the curfew, which began at 6:15 pm on Wednesday, will continue till 7 am on Thursday. However, he later said the curfew has been extended indefinitely.

Defying the curfew order, protesters were still on the streets of Guwahati where most arterial roads were blocked.

Dibrugarh District Magistrate has also ordered the closure of liquor licensed premises from 4 pm on Wednesday for "preservation of public peace and tranquility", news agency ANI reported.

Protesters clash with police

As tens of thousands of anti-CAB protesters descended on the streets of Assam on Wednesday, clashing with police and plunging the state into chaos of a magnitude unseen since the violent six-year movement by students that ended with the signing of the Assam accord, Guwahati was placed under curfew.

The Congress party has, meanwhile, called a shutdown in Tripura on Thursday.

Although no party or student body had called a shutdown in Assam, protesters, a majority of them students, fought pitched battles with security forces, including in front of the secretariat, the seat of the BJP government. Police fired tear gas shells and baton-charged protesters, who fought back.

Assam smouldered with protests rocking several parts of the state on the day the CAB was hotly debated and passed in the Rajya Sabha after its passage by the Lok Sabha on Monday.

According to student leaders who went live on national TV, many agitators were injured in police action in front of the secretariat.

All senior civil and police officials were incommunicado but, according to unofficial accounts, hundreds of protesters have been detained in Guwahati and other places like Dibrugarh and Jorhat.

An ambulance service was also hit in Kamrup metro due to a road blockade.

Police opened fire in Assam capital Dispur to quell a protest by the agitators after water cannons, baton-charge and tear gas failed to rein them in. Police also fired at Ulubari, which is barely 500 m from the state police headquarters.

A large number of agitated students blocked the road near the secretariat complex and pulled down the barricade erected on the arterial GS Road, provoking police action.

Police burst teargas shells and baton-charged the protesters, who were seen lobbing back the shells at men in uniform. They also damaged a stage erected on the road for Prime Minister Narendra Modi's proposed summit meeting with his Japanese counterpart Shinzo Abe on Sunday.

The agitators pulled down hoardings and banners advertising the government's welfare schemes and made a bonfire of those before the secretariat, damaged the police commissioner and joint police commissioner's vehicles, set on fire buses and other vehicles in scenes reminiscent of the six-year movement by students against illegal settlers that ended with the signing of the Assam accord in 1985.

In a rare show of solidarity with the protesters, government employees at the secretariat wore 'gamosa', the state's symbol of honour, and stood behind the gates and chanted slogans against the CAB. The Assam Secretariat Employees' Association also issued a statement supporting the protests and opposing the CAB.

(With inputs from agencies)