Angry demonstrators in northeast India Sunday threatened to continue demonstrations against a controversial new law granting citizenship to non-Muslim immigrants, with the death toll from the clashes rising to six.

Tension remains high at the epicenter of the protests in Guwahati, the largest city of Assam, as police patrol amid tight security.

The new law passed by parliament on Wednesday allows the Indian government to grant citizenship to millions of irregular immigrants from three neighboring countries on or before December 31, 2014, provided they are not Muslim. These countries are Pakistan, Bangladesh and Afghanistan.

In Assam state, four people were killed after the police shot them, while another person was killed when a shop was sleeping in it, while a sixth person was killed after he was severely beaten during a demonstration, according to what officials announced.

About five thousand people participated in new demonstrations in Guwahati at the sight of hundreds of policemen, and the participants chanted anti-law slogans and held banners saying "Long live Assam."

The law raised Muslim fears, and the proposed changes led to protests in which residents who were dissatisfied with the influx of Hindus from Bangladesh, who would benefit from the law, would participate.

In West Bengal state, where protests continued for a third day, the state's prime minister, Mamata Banerjee - who opposed the passing of the law - ordered a cessation of Internet service in many areas.

The demonstrators set tires and organized strikes on highways and railroads and set fire to trains and buses, and authorities pushed riot police to disperse the protesters while stopping train services in some areas of the state.

Side of the protests against the Nationality Law in Delhi (Anatolia)

Injuries
In New Delhi, many buses were set on fire, and a video recording on social media showed the police firing tear gas at the demonstrators.

The agency "Press Trust" Hindi that about 35 people were injured in the clashes were taken to hospital, while the authorities said that the schools in the area will be closed on Monday.

Indian Prime Minister Narendra Modi blamed the protests against the opposition Congress Party.

"To give respect to those who fled to India and were forced to live as refugees, both houses of parliament passed a bill to amend citizenship," he told a gathering in Jharkhand state.

"The Congress Party and its allies are inflaming anger over the citizenship law, but the Northeast residents reject violence ... They (Congress Party supporters) resort to arson, because they have not succeeded in that," he added.

Islamic groups, opposition and human rights organizations believe that the law is part of the Indian Prime Minister's Hindu national program to marginalize the Muslims in India, who number about two hundred million people.

Rights groups and a Muslim political party challenge the law to the Supreme Court on the grounds that it contravened the constitution and secular traditions in India.