NEW DELHI — Protests broke out for a third day in northeastern India over the country’s new citizenship law, forcing the postponement of an upcoming summit between India and Japan.
The citizenship measure, which was approved by the country’s parliament on Wednesday, makes religion a criterion for nationality for the first time. It creates an expedited path to citizenship for migrants who entered the country illegally and belong to one of six religions — excluding Islam.
Opponents say the law is discriminatory and violates India’s Constitution. Indian Prime Minister Narendra Modi has defended the measure, which is limited to migrants from Pakistan, Afghanistan, and Bangladesh, as an effort to help persecuted religious minorities from those Muslim-majority countries.
In India’s northeast — a collection of seven states that share borders with Bangladesh, Myanmar, and China — the passage of the bill sparked violent protests in which two people were killed on Thursday and 25 injured by security forces, according to a senior police official in the state of Assam. Police also detained more than 1,000 people across the state.
The unrest prompted the cancellation of a three-day visit by Japanese Prime Minister Shinzo Abe, who was scheduled to meet Modi starting on Sunday in Guwahati, the largest city in Assam. The governments said they would reschedule the meeting. The British government on Friday urged its citizens to ‘‘exercise caution’’ if traveling to India’s northeast.
Many in the region see the law as a threat to their indigenous cultures and languages because it allows migrants who arrived in India before 2014 to become citizens. In Assam, the region’s biggest state, tensions have existed for years between Assamese speakers and Bengali-speaking migrants who have crossed a porous border with Bangladesh.
But the scale and ferocity of the demonstrations against the citizenship law appeared to take local authorities and the central government by surprise. While the law includes a nod to their concerns — the migrants are not allowed to settle in certain areas designated for indigenous people — protesters said the measure was still intolerable.
On Friday, several thousand people gathered in Guwahati in defiance of an official curfew to conduct a day-long hunger strike to protest the citizenship act. Tanmoy Das, 22, a university student, wore a traditional Assamese scarf around his neck as well as a placard expressing opposition to the citizenship law.
‘‘The people of the northeast are different; our fears are different,’’ he said. ‘‘We don’t want any Bangladeshis.’’
The protest leaders said that this was just the start. ‘‘The movement in Assam will intensify, and the legal fight against [the citizenship act] will continue,’’ said Lurin Jyoti Gogoi, general secretary of the All Assam Students Union.
Thousands of people also marched Friday in Shillong, capital of the state of Meghalaya. Security forces fired tear gas and charged the crowd while swinging batons, injuring at least 60 protesters.
Earlier, protests also erupted in other parts of Assam, as well as the states of Tripura, Manipur, Meghalaya, Nagaland, and Arunachal Pradesh. Some burned vehicles and threw stones. Flights were canceled, a railway station was torched and offices of political parties attacked.
‘‘Never have the people of the Northeast felt so helpless,’’ wrote Patricia Mukhim, editor of the Shillong Times. ‘‘As small tribes struggling to fit into a nation, the only safety valve we had up until now was the Indian Constitution.’’
To quell the protests, authorities shut down mobile and broadband Internet connections and called for help from the Indian army. They imposed curfews that restricted movement, although such measures were relaxed in certain areas on Friday. Protests also spread across the country. There were demonstrations against the new law on Friday in Delhi, Kolkata, and Aligarh.
Modi tried to calm the furor in the northeast. ‘‘I want to assure my brothers and sisters of Assam that they have nothing to worry,’’ he wrote on Thursday. The government is ‘‘totally committed’’ to safeguarding the ‘‘political, linguistic, cultural, and land rights of the Assamese.’’
Modi accused the opposition Congress party of spreading fear and said Indian citizens should not be alarmed by the new citizenship law, which focuses on migrants.But Modi’s second-in-command, Home Affairs Minister Amit Shah, has repeatedly stated that the new citizenship law is a precursor to carrying out a nationwide registry of citizens. The registry would be modeled on an exercise carried out in Assam, where residents were forced to provide documents going back decades. Nearly 2 million people were left off the final list and risk becoming stateless or being deported.