Protesters in northeast India claimed victory on Wednesday after a bill that the government says will help Hindus in neighbouring countries settle in India lapsed before it could be ratified by parliament.
The Citizenship Amendment Bill is aimed at helping Hindus and members of other non-Muslim minority communities in neighbouring Muslim countries move to India.
But critics say the legislation is as an attempt by Prime Minister Narendra Modi's Bharatiya Janata Party (BJP) burnish its Hindu-nationalist credentials ahead of a general election, that must be held by May.
The bill had incited exceptional opposition in remote, ethnically diverse northeastern states where for years residents have complained that migrants from Bangladesh are a burden on society.
For days, protesters have taken to the streets, bringing chaos to several cities in the region. Authorities have responded with curfews and blocks on broadcasters in an attempt to quell the unrest.
The lower house of parliament passed the bill last month but it was not ratified by the upper house before the end of its last session before the election, on Wednesday.
Activists in the northeast welcomed parliament's failure to push the legislation through.
"This is a moral victory for the people of the northeast with the BJP forced to bow down to the voices of struggle," Samujjal Bhattacharya, a leader of the All Assam Students' Union, one of the protesting groups, told Reuters.
Members of the Assam state organisation had threatened to "shed blood" to block the bill.
Protests over recent days have also rocked the small state of Manipur, where authorities imposed an indefinite curfew and suspended mobile internet services for five days late on Tuesday, following violent protests.
Police said people were defying the curfew on Wednesday.
Protests also erupted in Mizoram state, where some activists have given voice to old separatist aspirations.